Loosing weight and exercising

Hey Mamas,
I am in dire need for some advice and just went out so apparently I’m 12 weeks postpartum and I started gaining more weight roughly around 12 kg’s. Since I started breastfeeding. It could be because of the sugar cravings that I have had but I’m trying to control that and be on a protein diet. I would really appreciate any advice that comes in in terms of how far I can go in the gym while working out or do I just stick myself in terms of walking or how many steps should I target to start losing more weight that would really be helpful because this is my first C-section I am very unsure how to begin about it and eventually how to go ahead so that so that I can start working out and lose some weight.
I need advice would be very appreciated