I swear to god, if I hear another person blabbler about the BMI I'm going to shoot myself in the eyeball.
BMI is not, and never has been an accurate way to determine if some one is healthy or not. If I calculate my BMI with my football playing weight, when I ran a 5 minute mile, a 4.45 40 yard dash, could bench press 225 @ 10 reps, squat 405 @ 8 reps, dead lift 515 @ 8 reps and weighed 190 lbs on my 6 foot 1 inch frame, I would have been considered overweight. My buddy is 6'3 and 250, all muscle, his BMI would be 31+, which would make him technically Obese, but I'd dare you say say that to his face. My trainer is 5'11 and 210, his BMI is 29.3, on the border of obesity.
People have larger frames than others and are able to support more weight than others naturally, which is why some people are naturally bigger than others. It's not rocket science to figure out that human beings an amazingly diverse and race and as such there is no universal code or index that we live by that is appropriate to determine our health needs, and how healthy we are. 6'1 and 355 is big, but without looking at him and seeing how that weight is distributed, implying that some one is obese is flat out wrong.
To the OP: I am a member of the Powerhouse Gym in Tampa, and their membership rates are ridiculously cheap, I paid $150 and i have a full 6 month 24/7 membership. They've got people there who craft diets and workout routines to help people do basically everything. I don't know what they have in your town, but if you are looking to lose weight look @ powerhouse. They're a lot cheaper, and in my opinion better than a Gold's (of which I used to be a member).
I'd recommend a circuit type routine to get your heart rate up, start getting your muscles/joints accustomed to working out, and also to help tone down some subcutaneous fat around them.