Cage setup question.

Hi, I recently purchased a normal ball python. I'm not exactly sure on the age, she is about 18 inches long. Is it ok to start her off in a 10 gallon tank at first and in about 3-4 months move her over to a 20L tank? I am worried that in the 20L she might feed a little vunerable with the extra floor space. and in the 10g I try to make it so she has plenty of space to hide.

10g is fine. Snakes can get stressed if they have a large amount of space. Ball pythons like being nice and cozy in a hide that's snug.Grats on the new baby. Make sure you have a screen top and clips for the lid to make sure you don't end up with an escapee.

I dug through the husbandry page: "For juvenile BPs up to 2’ a 10 gallon (or equivalently sized) enclosure is adequate. For adults an enclosure 36x18x12” should provide them with enough room for the duration of their lives."- Quoted from the sticky at the top.