Triathlon - need help with bike situation

So I have been looking into triathlons for some time now and I need help with my bike options. Currently I ride a trek mountain bike that my uncle gave to me and it is just a standard bike nothing special. What should i do to convert it into a solid beginner triathlon bike? I don't know much about triathlon bikes at all so should i get a whole new drivetrain set up? Should i get aerobars? Also i have a road bike frame that i found at a garage sale. It is stripped, would it be better to build that one up? I'm a college student so i dont have that much money looking for the cheaper better option. Thanks

Get a pair of slick tyres for your Trek and you're good to go. Aerobars would maybe be useful.
By all means build up your road bike frame - lots of cheap parts on eBay. It's a fun thing to do and a good learning exercise regardless of whether you use it for tris or racing.
As a college student, do you maybe have a friend of similar size who has a road bike you could use on race day?
Check the threads at the top of the page for advice on building up budget ' tri' bikes.
Best of luck.

Don't bother, go on craigslist and by a $150 road bike from the 80s it will be cheaper and faster. Aerobars are useless on a mountain bike. Aerobars on a mountain bike are less aero than base position in a road bike. You might want to consider the build, look on ebay. You are probably looking at about $300 in stuff (very cheap drivetrain, cheap wheels, seat, seatpost, handlebars, etc.). The craigslist road bike might be a better option. Just lube it up and don't use WD-40.

Just for our perspective what is your budget? Don't worry I'm a college kid too, but I'm broke from buying my bikes.

my total budget is about 200. but thats over the next couple of months. i probably going to build up the frame and keep my mountain bike as my mountain bike.

Yeah just get a pair of slicks for now. aero bars won't do you any good.
If you have a friend that will let you borrow a bike for race day do it.

My first triathlon I did with a $50.00 mountain bike with no mods.

Not competitive but fun and a good work out.

Go ahead and get a pair of slicks for the MTB. For the first tri, just go out there and have fun. If you enjoying it, then spend the money on a road bike.

if you want to be competitive, you will need a road bike. If you want to be wrecked on the bike, go with the mtb.

I did my first three on a MTB with big knobby tires. It can be done. It can't be done without a lot of effort!

The first one is a good learning experience on what tri's are all about. You'll gain a lot of valuable information to prepare you for future ones.

My experience commuting on a mtb with slicks versus a road bike is the road bike is 4 mph faster. Clip on aero bars will give you another 1 mph. So once you get your road frame built up with aero bars, you will make a big improvement.

if you want to be competitive, you will need a road bike. If you want to be wrecked on the bike, go with the mtb.

Case closed. Take sirious94's advice and find a cheap used road bike (pref. 2200 or Sora equipped and no more than 23 pounds) on CL. Go find a road bike AND sign up for your triathlon immediately.

I'm not afraid to admit that I have been passed, on my full TT rig, by better cyclists on mountain bikes with skinny tyres.

It's all about the engine.