Monster88

I'm a learning mechanic and I'm wanting to pretty much restore my jeep that i picked up for around $550+Registration and Tag costs. I know how to do a basic tune up but I'm wanting to get more mpg and up the performance in my jeep.
It has around 2232xx miles on it, still runs and drives. I'm slowly able to do minor things to it due to money issues.
Can anyone help me find a inexpensive way to up my mpg and performance? Maybe give me tips on how to help improve those things?

Also i have this noise that sounds like its coming from the front end but its not a constant sound. It only happens when I'm in drive and rolling but only when I'm pressing on the gas, otherwise when i let off it goes away. Can anyone let me know if you have or had the same problem and/or if you can tell me what i can do to fix it?