u/Arsenic-Arsenal

I've had this booklet for over a year and I'm so scared of f-ing it up.

I can't find proper info. Should I take the pages out to wet it/stretch? If not, will it bulk when painting wet-on-wet? Can I even do wet-on-wet? HOW DO I ONLY WET ONE PAGE AT A TIME ?!
How do I make sure the paint doesn't leek to the other pages? Should I put a plastic sheet under? Or WAX paper? Should I use washi tape?

Please help me! I really want to use it.

Unfortunately, Canadian YouTube is shit and I haven't found clear info on that... Like explain to me like I'm 5 yo please 😭