We’re lucky that several great free databases exist for you to download for your pleasure and with few restrictions. They are also quite thorough and exact with artist tagging as well.
My longest running favorite would be Ex-Hentai. Hopefully you’re already aware of how 
to avoid Sad Panda by registering and logging onto E-Hentai first and then switching the url to Ex-hentai to get to the loli section. There’s torrents and simple downloads with credits. It’s really not that hard. There’s doujin, manga, cg, western art, and much more.
I only came across Nhentai in 2016 and I’ve been actively using it the most ever since. Torrent dependent and with great tagging. Unlike Ex-Hentai you don’t use zips on torrents and it’s a little simpler to use and get in. A lot of toddlercon is missing, as is all CG, but that’s it really. Also check out ImHentai which is a new clone of it and has some Western art too. Similar to Ex-Hentai!
Hitomi.la has a good selection and direct download (a bit slow) as well as readable galleries and tagging like the other 2. Unlike nhentai there’s some cg uploads too although the site does have some gaps and slower responding features. It does have a lot of toddlercon that’s missing from the nhentai as well.
Erocool.com is a rather new website with a lot of new content from the last 2 years. Good for reading online. HentaiShark is good too.
PurinPurin has good selection of translated hentai, including lolicon. Give it a look over as it has some good tagging in place. Oh and Little White Butterflies is back now !!
HBrowse is another Hentai Translation site with many great lolicon stories posted routinely. 3 to 5 new ones daily? Wonderful!
HentaiFox yet another doujin site with mostly English translations and Artist and Character tags. Hentai Lolicon is not bad either.
Tsuminto has a load of translated hentai tossed together.
SVS Comics has Hentai, 3D Comics, Western, and more. No loli 🙁 Maybe go to GoToFap and have some better lucks perhaps.
Hentai2Read, Have I mentioned English translation loli? or LoliVault for Spanish!
Finally, Doujinshi.org is the best dbase to find info on hentai and manga. There’s no download options but its a great site to find as much data as you can find on an 
artist, an anthology, and hentai from over the decades.
That should be enough to help you find via searches which artists and doujin you are after. Have fun mass downloading!