You can have as many characters as you wish. You can even exchange items an money between your characters, though you're not supposed to go overboard with this. Don't be your own economy and you'll be fine.
Note that playing multiple characters
at the same time should first of all not be possible, and is otherwise a no-no if you get around those restrictions and get found out. It's fair play for items to be gifted remotely, by whatever means, though. I personally try to maintain a Chinese Wall between all characters, inclusive of knowledge gained. But that's an extreme POV.
Priests tend to be slightly hardish, but I have no experience with them. They don't seem to be too hard as they have very accessible guildhouses.
The Ankh-Morpork temple to Fish isn't near the others (clustering in the 'faith quarter', as it were), but didn't seem to suffer too much from lack of recruits last time I thought to do a head-count, cross-compared with city of origin.
No idea how many of those are true-newbies who stumbled in, entranced by the write-up on the descriptions of each god, or just new-characters by those expanding their 'portfolio' of experience, but my most senior current character became a Fishite as a newbie, having not played for nearly a decade, i.e. since before the creation of the terrains and reorganisation of Ankh-Morpork, on top of everything else, so I was definitely green before I decided to turn aquamarine.
@Sappho: Doing nothing will earn you some XP. Going to new places will earn you XP (though be careful in places that have warnings up, e.g. The Shades/Snail/Medina, and go too far out into the 'wilds' and you may find dangerous creatures like yeti). Using various commands (especially your guild-specific ones and various craft-related ones you can pick up, type "commands" to see if you have any of those) that are GP-using will return you some XP (teaching skills will also give you XP, but that's probably not realistic when you're low on the ladder).
Frexample, a priest can pray, exchanging Guild Points for a proportionate amount of XP. Although repeatedly praying will give reduce that proportion, so doing other things as well is advisable (different rituals, and different activities like sneaking/watching when you have enough GP to spend some on the non-faith activity concerned).
A lot of new players these days start up by finding (or stumbling upon) quests that these days give XP (indeed, they didn't use to, but they once did before that), and while I never did chase those (and tend not to use knowledge from one character to help another character along), there is now (a fairly recent change) an
official quest hint/list thingy that a newbie could use. (IIRC, my first completed quest in the 'modern' era, beyond the newbie area of the time, was "Polite Shopper". I'd not even realised it was one. But, then again, that was back when there wasn't XP either, just the CCCs).
I can think of one more way to get XP, and there's also the TM (TaskMaster) system where something you do (or try to do, but are on the edge of) enough may trigger a skills upgrade in the leaf (or one of the leafs) of the skills tree that the skill uses, which is XP-saving. (One non-priest character of mine never advanced any faith-tree skill, but through mending the odd piece of clothing at the altar of Gapp ended up with a level of fa.po well into the double digits. Though as he never intends to use faith, this might be considered useless for anything other than the next time he tries to mend clothes at the altar of Gapp.
