You'll be lucky if yours ends up regular. The short answer is that they poop when they feel like it and not a minute sooner, though things like a shed or a thorough cage cleaning might tempt a bm out of some snakes. Don't be concerned if you go a few weeks and/or meals between poos, this is normal.

Urates happen more frequently, and can come either as hard pebble like substances or as a wet mess (or both!). As long as your bp is eating regularly, has good humidity and access to fresh water, Urates once a week or so is reasonable. More or less frequent still isn't anything to be concerned with most of the time.