Well, I can sympathize with the PE thing. Testosterone does build muscle and density, but everyone has different levels of strength. To actually build muscle, it's a lot harder as a girl than as it is as a guy because of the lack of testosterone obviously, however that doesn't mean you can't get stronger than the average woman.
Same approach, start off with light training. You want every day after an exercise on a major muscle group for your muscles to rest, so make sure you get good sleep and eat right so they can grow. Diet is extremely important, I don't mean eating less, I mean eating right. This is how I did it:
Monday:
chest, triceps, calves
Wednesday:
back, biceps, shoulders
Friday:
thighs
You can break this up to up to 5 days, just as long as you don't do two big muscle groups on the same day. You can even mix in some cardio if you want. Just start light.
If you don't want to bulk up but get stronger, don't worry, pre-T you'd have to really work at it and take supplements. If you do want to bulk up, still start light because the biggest mistake you can do is overwork yourself and then you have to let your muscles rest and by that time you might not have the motivation to keep at it.