Here are some tips that I can offer, because when I started out, my first character was laughably built, and that made PvE, whether solo'ing or with a party, nigh-impossible. I've learned a faint amount since there.
Never be encumbered. EVER. It puts you at a serious disadvantage, because, quite frankly, y
ou're going to be running a lot. There is always going to be a moment where your character simply can't win, and you're going to need to leg it as soon as possible, and if you're carrying tons of stuff, you're going to be a sitting duck. If you are carrying too much, utilize the Vallaki Warehouse, which is an excellent resource, honestly.
Mages/clerics are easy mode. I am not sure how how you're building your sorceress, but I think you're missing out on spells that are essential for lowbies on this server. Ghostly Visage is one of these essential spells, as it basically takes the bite out of those rat swarms you're having trouble with. The dire rats, likewise, won't be able to hurt you, and the only thing you'll need to worry about will be the wererats, which can easily be taken care of with a 2nd-level offensive spell.
Generally, though, at low-levels, you'll have to play it safe on your sorceress, recruit a party, and then buff up those who are in your party doing the dirty work with certain spells (Bull's Strength, Cat's Grace, and/or Flame Weapon). Oh, and get a familiar with DR like a Mephit or a Raven if you're really having trouble and need something to take some of the heat off of her. They don't do massive damage, but a Raven familiar of mine pretty much plowed through a swarm of rats, true story.
Know where you are, what's there, and what you can deal with. Chances are if you don't know where you are and are all alone, you done goofed... mostly because you don't know what will spawn and might take your character by surprise. This is not a server to go around exploring, in hopes of finding something new, because more often than not, the 'something new' will try to murderdeathkill you into oblivion. This is especially true if you go to the north, where a host of loup-garou (werewolves) are just dying bring you home for dinner.
Get a haircut, and get a real job. Get a job in-character, even if it is something as simple as collecting herbs along Old Svalich Road during the daytime for herbalists (which generally pays more than gathering milk pelts for Petre). Alternatively, join the Vardo, start a mercenary company, do something that will net you the LOADSAMONEY needed to get that Hektor's Kutter that's for sale. Right now, my level 5 character has an absurd amount of money and it hasn't been from farming, but instead from running a player-supported and ran theatre. The most money I've gotten as a low-level hasn't been from farming.
Derp is inevitable. Some things are unavoidable. There are going to be occasions where something stupid leads directly to your death, like lag problems. The important thing is to take it in stride. One important thing that I think needs to be mentioned is you don't EVER respawn, unless as a last resort. You retain all your experience as long as you DON'T respawn, so go around as a ghost, haunt people in an effort to get them to rescue you, and... well, you might be short on fang, but at low-level, what is needed to raise you is small potatoes.
I hope that these tips are helpful to you, as they were things I had to figure out all the hard way. The server has a steep learning curve, but I think you've seen by the replies here that neither the other players nor the DMs are trying to go "GOTCHA" and make the world more difficult for you, but actually want to help out a new player who is confused.
