If you want to lose weight, I'd say diet is number 1.
You can kick-start it with a "cleanse" which might help act as a circuit breaker if you've gotten into a bad eating rut. I'll mail you a copy of one.
As for exercise, you don't need to wait for a gym buddy, you can get started TODAY without even going to the gym. There are loads of exercises you can do: push-ups, sit-ups, planks, yoga, stretching etc can all be done at home. Check out youtube if you need a guided routine or instructions on how to do them correctly, there are tons of videos that would be suitable.
I completely agree with WickedRyan, start off slow and build up in increments, just make sure you GET STARTED!
If you really need to go to a gym and have a real life gym buddy, then work with a personal trainer until you find a buddy (don't let the fact you don't have a training buddy act as an excuse or reason not to get started). A PT can provide the external motivation you are looking for from a buddy. They can also give you nutritional advice, show you the equipment in the gym etc.
This is all on the assumption there isn't an underlying medical reason for your weight.