I would like some help with developing a routine

Hey. So I got a membership at the gym this past Friday and had a meeting with a trainer because I'm aiming to lose 100-150 lbs. Well he did very little in the session and wants a buttload of money to continue, which I can't do. I'm wondering if anyone could help me with coming up with a routine or know of any great websites/youtube etc.. for them. I really like doing things like medicine balls and using my own weight type things, but am open minded.

Thanks ahead!
Christina