Best diet while pregnant?

Kaitlyn • 💍07/09/16 Mama of 1 as of 12/23/19💕 TTC #2

I just found out I'm pregnant after 2+ years of infertility!

I'm currently around 4 weeks! I'm pretty seriously overweight and really wanna be healthier for myself and my baby. I plan to start walking a couple times a week with a friend of mine for exercise, but am wondering what's the best diet to start or try while pregnant.

Please help. :)