@Renown0
Welcome to the painting challenge. @Caedrus is the host for this year's challenge, so any questions you have you can direct it to him.
In previous years you had to join before April, but this year we have a buy in system if you've missed the early months
If you look at the start of this thread there's a rules section.
To start with pick a pledge level from minion to tyrant. This will indicate how many soulstones worth of models you have to paint every month. Your allowed 2 mulligan months but as your starting late, Jan/feb will both be mulligans. So to join in May at Henchman level you'd have to paint enough stones to cover March and April (an extra 22ss worth for Henchman)
Check with @Caedrus but I'm not sure that you have to paint those all at once, I think you could do an extra 11 this month and an extra 11 next.
That sounds like a lot of rules, but the painting challenge is really just about having fun, challenging yourself and being part of a group that encourages each other to achieve their goals at any level