Before you start with exercises check if you have diastasis recti and do appropriate exercises to fix it first. Otherwise some ab specific movements (such as planks and crunches) can actually make it worse.
I would start with walks with your baby every day if not already doing it, if possible switch driving/taking public transport for walk. There is also lady on YouTube who does pp workout depending whether you had natural birth or c section and you start very slowly, going 10-15 min exercise But overall you have to love your postnatal body whether it’s big or not up to your expectations ☺️ you got this mama
Baby2body