probably an easy question here,
I need new tires, and want to go with something thinner. I have 700x32 that came stock on my bike, would I be able to get away with 25, or would 28 be the smallest I should go? It probably depends on my rims, I'll measure them next time I go to my garage and update with that as well...

There's a table with recommended tire widths as a function of rim width, but in my experience you can usually go well outside the recommended values without any problems. On my touring road bike I run tires ranging from 23mm up to 38mm on the same rims and have never had an issue with any tire width. So I'd think you could go with 25mm (or even 23mm) tires if you want.

First you should measure the inner width of the rim. As you are mounting 32 mm tires, the inner with will be (typically) around 16 and 19 mm. If the width is around 16 mm you can mount 28 mm tires without problem and probably 25 mm tires. If it is around 19 it will be difficult to fit 25 or 28 mm tires but the latter could fit, depending on the shape of the rim.

NOTE: I am talking about rims with with inner lips to hold the tire.

No problem. Even relatively wide rims accomodate narrow tires. The popular road rims now are 18mm internal (23-24mm external) and use 23mm tires easily. The tire will have a more round profile and may measure slightly wider when mounted on the wider rim.

Look at the rim manufacturers web site. They usually say min and max widths.

https://sheldonbrown.com/tire-sizing.html#width

Um, no.

Just for kicks and grins, I took my cross bike out to the club road ride the other night. Just felt like riding it, and if it kept me in the slow group, oh well. It's been hot as heck anyway, and I already rode that morning.

32mm mostly-slicks on the cross bike.

Still rode with the faster guys. Hardly felt slowed at all. A tiny bit maybe, but the numbers at the end were hardly significantly different. And, it was fun.

I measured the outside of my rims last night (I don't really want to unmount the tires that are on there right now, until I get new ones, scared they might just fall apart and not be able to go back on) It's 23.1mm, and I read around online and someone did put 23mm tires on the same bike/rims that I have.
I ordered a pair of CST correre 700x23c tires, hoping they will fit ok. I do know if they do, my ride will improve a lot.

So here's another question, how big of a difference will this make, from a 32c POS to a 23c cheap but way better tire?

Why worry about size? I've got 32's on one of my bikes and they are as fast as my 23's. Maybe just get a better 32. Look at Compass Bicycle and get a pair of the Grand Bois Cyprus 32's. Very comfortable tires and very fast. As light as most 23's. I hardly ride my Orbea because the Soma is just as quick and MUCH more comfortable to ride.

When I put 25s on my S1 I do go significantly slower. Which tells me that even though it looks like there's just enough clearance, there really isn't in real riding circumstances.

any difference in tread between old and new tires? if not then the only difference you will likely see is an increased interest in where the tire goes on the pavement. with a wider tire you can be more careless. taking that to the extreme big fat tires can roll over almost anything.

I'm still seeing what I like as a road rider, So going extreme differences in tires I think will give me the best idea of what i like more.

The tread difference is very large, the tires I have now are very similar to something like this


where the ones I ordered are slicks. I don't plan on riding on any wet conditions at all, and areas that I ride are paved trails with no cars/traffic allowed, so gravel, pot holes or any other bad road condition will be little to none.

You are going to like 23's MUCH better than the stock 32's. But don't think that this applies to all 32's. Not all tires are created equal.

THis is soooo true. I found that out on my mountain bike when some (explicit comment here) kid, i'm guessing, slashed my kenda tires, and I was strapped for cash so replaced them with cheap no-name tires. It's scary the difference in a decent tire vs a crap tire.
Ya, the ones I ordered are cheap, but probably still way better than what is on my road bike now...