If this is a newbie question, then you must be a beginner. So: just continue doing the basic exercises and don't start with too much. But if you feel your penis is ready for it then you can do more. Btw: stretching is not a necessary warm-up for another work-out. It's a work-out that's good for a warm-up, but many guys do their work-outs seperately. So if you are ready, you can do as many work-outs after your stretching you want to do.
Good luck.