Hey Denim, welcome to P99!
What server are you playing on (Blue/Green/Red)?
Clerics in this era are a great grouping/duo class. They are slower but capable of solo. From what I understand, grouping is pretty strong on Green still, so your best bet may be to play on green, get groups when you can and solo when you can't. If you are dead set on solo, or not, take a look at Swish's Solo guide at the bottom link. The New Player guide is just general information that is relevant to the P99 servers.
P99 New Player Guide
https://wiki.project1999.com/Players:Newbie
Swish's Solo Guide
https://wiki.project1999.com/Swish%2...ric_SOLO_guide