Potty training

So my 15mo old son he's been very interested in the bathroom lately going in when I go going in, when his dad goes and I'm taking that as a sign that he's getting curious about going potty. so I want to start potty training him or at least sitting him on the toilet and getting him the idea of being on the toilet to pee or poop. Any suggestions on how to do this. Lol any app suggestions anything would be appreciated.