When do you start potty training?!

M

Hi! First time mom here. My son is 21 months old. I’m curious as to when others started potty training. My son is/has been interested in the potty for a few months now (flushing it, etc.) and now he’s also started letting us know when he needs to be changed or he will try to take his diaper off and grabs at it as if it’s annoying him. He does understand most/if not all the things we say to him but he does not have a really large vocabulary yet.

I just bought all of the stuff to start like a toddler potty, training underwear and pull-ups but I don’t want to start too early and have a long drawn out process (i know it will take awhile, i just don’t want to start if he’s not ready and fully understanding) we’re also going on a family vacation in 6 weeks that includes a long car drive (9-10 hours) and I’m a little worried if we start potty training now that he will still be in the process of it and we will have a lot of accidents during the drive.

Any help is appreciated! What’s the normal age range? What are some of the signs that they are ready? How long does it normally take for them to catch on? Thanks!!