Fitness

First time mommy here, and I was wondering what are some exercises that i can start doing after my six week postpartum check-up? when can i go back to running?
I would like some suggestions of how to get fit. (I went for my six week check up the dr didn't say anything...so I'm assuming i got the greenlight to resume to my old activities)
I would to hear everyones story of how and what they did to get fit after pregnancy.