First thing you should do is memorize your spells. Do that by opening your inventory and opening your spellbook. Click on the spell paper and put it on a slot in your spellbook. It will scribe the spell in your spellbook. Then you click the spell and pick a spell slot in your spellbar to memorize it. Once it is memorized, you can cast it. The Minor Shielding spell can be cast right away without a target. It temporarily gives you +10 hit points and a minor armor buff. You always want to have this cast since you won't have a lot of hitpoints as a necro.
Next, take the note you have in your inventory and go to Neriak 3rd Gate. You can use the map of Neriak at
http://wiki.project1999.com/Neriak to find your way there, or just ask anyone in /ooc, /tell or /say to show you the way. Most people are helpful. Then give your note to the NPC it instructs you to. You can read the note by right clicking on it. That will give you a little bit of experience and your first robe. Equip the robe and dagger.
Next, head outside Neriak and start killing things. Don't just run up to every monster and hit attack though. Level 1 might be the hardest and most frustrating level to anyone who's playing the game for the first time, because you will die very easily. You want to get in the habit of "conning" the mobs. Left click on the monster, then press "C" this will tell you how hard that monster is going to be. At level 1, the easiest monsters will con White, that is, the text telling you how hard the monster is will be colored White. It will say something to the effect, "soandso regards you indifferently -- It looks like an even fight." Monsters that con with yellow text are a bit harder than white and will likely kill you. Red monsters will wipe the floor with you. Blue monsters are easier than white monsters and give less experience than white monsters, but this will be the primary monster you want to attack going from level 2 on. Monsters that con green typically don't give experience.
Conning the monster will also tell you if it will attack you outright if you get too close. If it scowls at you ready to attack, or glares at you threateningly, that means it will "Kill on Sight" when you get in its aggro radius. If it cons anything else like dubious, indifferent, amiably, warmly or ally, it won't attack you unless you attack first, or you are attacking one of its friends nearby.
Speaking of which, some monsters are social. If you are attacking a decaying skeleton and another wanders close by, it will "add" and start attacking you too. If you are attacking a spiderling, spiderlings will add. Even if the monster would consider indifferently normally. Some monsters are not social, like snakes. Usually the monsters with the better loot are social.
Try your best to to remember where you are and how you got there at all times. You will die. A lot. Especially at lower levels you're going to have to corpse run a lot. When you die, you go back to your bind spot and all of your stuff that was on you at the time will be on your corpse where you died. So you have to run back to your corpse and loot it to get your things back. It will take a full week of real time to rot. When it rots the only way to get it back is to /petition and wait patiently for a GM to bring it back and they will drop it in East Commonlands, so it's easiest if you just loot it yourself before it rots.
Save your gold for food, water and spells. Spells in this game are going to be your primary expense for many levels, especially this being your first character. You always want to have food and water in your inventory. If you get hungry, you won't regenerate hitpoints. If you get thirsty, you won't regenerate mana.
Anyway, the Wiki has almost everything you could need for finding your way around, monsters to kill and quests to do. If you need some in game help, /ooc your questions and most people will be quite happy to walk you through them. This community is for the most part quite helpful to new players, on any server. Just make sure you /who each zone your in, because if you're the only person in the zone, your /ooc will go unanswered.
This game is a grind and the first level is stupidly difficult for new players. Stick close to the guards at the gate until you feel more comfortable (but not so close they steal your kills). If you want, I'd be happy to hop on for an hour or two this weekend and walk you through a few things if you have difficulty. Good luck, be patient and have fun!