Hello! I'm a beginner myself but I do have something to share with you. Hitting the gym is a continuous process, and you should understand that you are not there just to gain some weight, then drop it altogether when work or college begins. You are there to live a healthier lifestyle, and to maintain yourself in that condition. You should set clear objectives before going any further.

Ask yourself what is it you want out of the gym, and how important is it to you that you achieve those goals? What is your level of commitment to this positive change in lifestyle? What will drive you on when the excitement wears down and things begin to look bleak and boring? These simple questions (and their respective answers) will help to motivate you in the long-run to excel and achieve the results you seek.

Good luck and have fun!