the government rules about shota/lolita is really sketchy but basically, this is the general thing about that
real life shota (I'm talking real legit cases of adult/child)- IS illegal
owning/looking at real life shota porno- TECHNICALLY illegal, but only if you're caught is usually the case
with explicit anime/cosplay/manga shota, loli, yaoi, and yuri, it's a different case because the characters are FICTIONAL and NOT physically nor situationally based off of real people (usually), and is generally labeled as fantasy/fetish material.
that said, shota/loli is totally legal, and as far as art goes, as long as it is your own drawings, cosplays, comics/fanmanga, you rate it appropriately (18+/explicit/whatever the case is), and you give credit to the original creator of the characters used, and if you sell them, stick to online and conventions; you will be fine.
hope this helps some