I sadly don't have enough money to take my wheels to a shop and get them trued. I do have a friend who happens to have a spoke wrench but is too busy to teach me how to do it. I've done some research and have a pretty good idea on what to do and what not to do. Does anyone have any advice or tips they've found makes it easier? Also I was wondering if it would matter if the tire was inflated or not? Thanks!

Go in 1/8th turn increments once the spoke tension is generally even by feel. At that point, tiny changes are all thats needed and you dont want to run out of threading on each spoke due to turning em all too much.

The biggest mistake novices make is turning the nipple the wrong way; they end up loosening the nipple when they think they are tightening it. This just happen a few days ago at the co-op; I showed a guy which way to turn the wrench, and explain to him about how to look at the wheel and not make that mistake, and yet he did it anyway and turned a minor truing into a huge mess. Bad on my part for not supervising him more closely. Anyway, nipples are threaded clockwise i.e. righty-tighty, lefty-loosey. But if you true from the bottom of the wheel, looking at the rim from the inside, you're looking at it upside down, and thus tightening appears to be loosening. I always tell people to look at the nipple from the outside of the rim so as not to make that mistake (but they do it anyway grrrr).

If the wheel is a better quality double wall rim, you do not need to remove the tire for lateral truing, but it helps if you are trying to true for roundness. On a single wall rim, it's not a bad idea to deflate the tire so the nipples won't dig into and possibly tear the (rubber) rim strip inside.

Turn bike upside down so wheels rotate freely. Apply a drop of light oil to each spoke nipple at the spoke and another at the rim. Adjust brakes so that pads are scraping the rim at a couple places, or use a clamp to pull the brake lever by the appropriate amount, or fasten zip ties to fork and frame then cut them and rotate them to touch rim at those places. Make sure spoke wrench fits the nipple snugly, i.e. is the right size.

Rotate wheel and see where one side of the rim touches a brake pad or zip tie. Find the two spokes on either side of that point that lead to the "opposite side" of the hub. Tighten those spoke nipples by 1/4 turn. "Tighten" means, if looking from hub to nipple, you are turning counter clockwise. Then go on to the next place where the rim touches, and repeat. You may not eliminate the touching with just one 1/4 turn adjustment, that's fine. Keep going around the rim, making 1/4 turn adjustments, sometimes to nipples you previously adjusted. Eventually you will want to start making 1/8 turn adjustments. After several trips around the rim, you should find the rim no longer touches anywhere. Then adjust the brake pads or zip ties to be closer to the rim, and repeat.

You are done when rim is true enough that it runs 1-2 mm from the pads or zip ties without touching anywhere.

If the spokes start getting too tight - unlikely, but you'll find the nipple difficult to turn with modest finger pressure - then you want to try loosening the nipples on the "same side" of a rim touch, instead of tightening the opposite side nipples. There are smartphone apps to check spoke tension by plucking/sound, I've never tried them.

Fine to leave tire inflated.

Note the above process addresses lateral true, not radial true. I wouldn't worry about radial true unless your wheel is badly out of round. It also doesn't address dish, but I wouldn't worry about that as long as your rim appears centered between fork blades or seat stays, which you can gauge with a ruler or a stick. It takes a pretty significant error in dish to be a real problem.

You can turn all your C&V bikes upside down but you are not going to work on my bikes.

Lateral is usually what people notice first when a brake shoe rubs the side of the rim. When you adjust for it remember you will affect the radial trueness as well if you dont balance out that tension. Tighten one side and loosen the other side at the same time to preserve your radial alignment. When you have lateral done then re-check the radial. Sometimes it takes a few tries to get it all right. If it WONT true up easily, you may have too much of a bend in the rim, and that takes a different finesse to repair.

As mentioned before, some lubricant is a good thing especially if you start your adjustment and hear squeaks or pops.

-SP

If these are old wheels, the nipples may be corroded on badly.
Not an ideal wheel for a beginner to learn on, because you have no sense of tightness.
A nipple may be impossible to turn, but still have a loose spoke.
They are also great at ruining spoke wrenches.

Get a decent spoke wrench. One that fits and grabs the spoke on all sides. The round things with multiple slots around it are pretty crap and round off tight nipples. You can use one to find out what size you need.

That's my best advise the rest here is also good.

If your bike has a drop handlebar and over the bar cable routing (aka non-aero) do NOT turn it upside down as that could kink the brake cables. Plus, turning the bike upside down can lead to scuffing the saddle.

I'dremove thetire and the rim tape so I can see if the spokes are protruding past the soke nippples after truing. On a single wall rim that can lea to punctures on the road.

Keep a piece of tape handey ie stuck to the truing stand or bicycle frame and stick that tape on the last spoke you're woroking on if you have to leave the wheel. That way you'll know where to restart when you come back.

Make haste SLOWLY! Do not try to true the wheel by just turning a couple of spokes a lot. Time and patience are your best friends.

If there's a co-op near you it might be worth your while to book a time with them when they're not too busy and they have someone to guide you.

Cheers

Thank you for all the replies, I appreciate it all, will definitely keep these things in mind.

You can turn even the nicest C&V bike upside down. Just put a towel under the saddle and books under the bars to avoid scuffing or kinking.

Or you can hang the bike from something, e.g. ropes tied around top tube.

Since OP doesn't own a spoke wrench, I assume he doesn't own a workstand. This is shade tree wrenching, like we used to do in high school or college.

I frequently turn my bikes upside down. I've got a couple pieces of cardboard (for that purpose) to lay on the floor first.