Two part question:

Trying to get magica fortify and destroy spells but I havent had much luck yet (I am going to the temples and the mages guild and arcane). I found one I think but way above my level (only 19). I tried training as well but I am now stuck there too as they dont let me train above this level.

Second part is how to get rid of a spell once tou have a better one.

Thanks

Unfortunately you cannot get rid of old spells without mods. You can buy sever magicka in the Skingrad mages guild, and absorb magicka in Anvil. To get fortify magicka, activate the Aetherius doomstone North West of Skingrad.

Two thoughts:

(1) if you're needing these spells for the Mages Guild's "Vahtacen's Secret" quest, you'll find those scrolls in a crate under the table near the pillar. The only spell that isn't there is the frost-damage one. That's the immediate solution to that particular problem.

(2) Cast-able spells and effects don't have much to do with your level and everything to do with your skill in that particular school. If your skill is low, you're stuck with lower level spells and effects. You can boost skills with Fortify Skill effects. There are not any spells that you can buy that will give you access to this effect without resorting to mods. I believe you can make it available at an enchanting or spellmaking altar by having the effect active at the time, however. Having the Skeleton Key (complete Nocturnal's quest to get it) in your inventory should be sufficient. At that point you should be able to create a cheap spell to fortify any skill, which will then allow you to make spells to fortify any of the 21 skills since it will be a known spell effect and you won't need the active effect.

A word of caution, though. I found this to be a majorly game-ruining tactic in Morrowind, so have not really tried it in Oblivion. Try it at your own risk.

On the spell removal issue, it can't really be done in-game, but there are a few mods at tesnexus.com that will do it. Just do an advanced search for descriptions containing "remove spells" to find them. You'll need to register to download, though. If you like the mod, please go back to comment or give an endorsemant.