1. take some time early on and level up
2. You can perform every spell from the beginning. You just need to meet the following criteria:
A: You have enough MP to cast the spell in question
B: You do the correct d-pad motion to cast the spell.
Don't waste your money at the librarian buying the spells. Just do a quick gamefaq
3. Use the soul steal spell, love it.
4. Dark metamorphisis will allow you to regain 8 hp for every enemy you kill that bleeds. This means bats, those zombies at the beginning, etc. Once you have enough mp for soul steal, this spell is pretty useless.
There are very few awesome weapons available to you at the beginning of the game. Most of the badass weapons come much later in the game. Kill Dhurons until they drop a werebane. If you do a hadoken motion with it and press attack you'll get a special move out of it. This is the weapon I stick with most at the beginning. You can find dhuron's in the library.
Oh, and once you get the crissaegrim you are officially a god.