You'll get a lot of on-line advice, some good, some bad. I'd suggest getting in touch with an RC club in your area. There, you will meet real fliers. If you don't know who or where, if there is a hobby shop in your area, that would be best place to inquire. Another place you can go to is the Academy of Model Aeronautics website, http://www.modelaircraft.org

http://www.modelaircraft.org/clubsearch.aspx link will allow you to locate a club near you. There, the club officers can get you in touch with someone to help you with advice on assembling your aircraft, may be even give you flight lessons. This will help you to avoid common and costly mistakes, and also get you in touch with people who can help you as well as a place to fly your airplane.

Also with a limited budget, you may find a club member that is willing to sell you a good used engine or perhaps even a new one for a reasonable price (or sometimes even free!).

Good luck in your build and flying.