If you didn't, then you've missed almost all opportunities for further utility spells.
Start with Wizard City in Olde Town, near the Bazaar. Make sure you accept every quest that Baldur Goldpaws has for you! He offers them at levels 20, 35 & 55. Also make sure Merle Ambrose doesn't have any left over quests. Use the Quest Finder in your log book to find out if you have any quests from these two.
Next stop, Grizzleheim. If Baldur already sent you there after level 20, go back and use the Quest Finder in your book to make sure you finished everything. If there's something there that you didn't finish, get started! Not completing Grizzleheim locks away many future quests and spells. After level 35 and the start of Mirkholm Keep, you'll earn Fuel.
After that, keep go through the rest of Grizzleheim and then Wintertusk until at least the start of Sudriland and the quest Su Su Sudriland. This one is the key that unlocks side quests for your level 55 spell (Power Link), the level 58 school pet, plus a level 75 minion and all of the later utility spells.
I am currently in Vestrilund (anyone wanna help me there?! )
Recently, I've been doing lots of Wintertusk, but my only problem is that I'm still in Dragonspyre. It annoys me all the time how people as lower levels have access to areas like Celestia and I don't. Thanks though.