mk4 or mk7, advice? Which to get, tips when buying, what to expect to pay?

Hello all this is my first post, I am here in need of advice and guidance. I have been a fan of the golf gti for some time now, I really enjoy the look for the mk2,mk4 the most.

Im finally old enough to buy my own car, currently am 18yr and in college. Im sure you'll probably say I could have bought a car earlier in my life. Which would be true and untrue at the same time. My father has been in construction his whole life and strongly discouraged me from getting a job, since he was forced to come her when he was 16 and work whilst sending money back to Mexico. He has provided me with a car since I came of age, not allowing me to pay a single dime back. For which i am extremely grateful.

Any way I am finally in a position to buy my own car preferably a beat one, I'd like it to be a project car. What advice would you give for someone new trying to go through the motions of getting and tuning/modding their first car? I'd like to make something if am proud of something to show off and say I'd did this.

Thanks and have a blessed day!