There are a few guides on the wiki
https://wiki.project1999.com/Players...pecific_Guides
This one has a lot of detail, amongst others.
https://wiki.project1999.com/Sesserd...Strategy_Guide
Necro like mage can level naked. The biggest problem in classic for necro is they can't be an iksar. Kunark rolls around. Anyone who wants to stay necro will re-roll iksar or tough it out without the regen.