If you're speaking about the Mage's Guild this skill line caps at ten currently meaning there are no more to be gained.

If you're trying to play a spellcaster/wizard style character you can use any skills which are Magicka based to good effect, most of the spells come from Destruction Staves, Mages Guild and your class skill lines.

When you open the skill menu, you should see all the skills available in each skill line. For example, for your class, there are three such skill lines, for each weapon type and each armor type there is one. You unlock more and more skills by levelling the whole skill line and you do so by slotting skills (class skill lines), wearing a weapon and slotting skills (weapon type skill lines), and wearing armor of the type in question (armor type skill lines).

So, your character level doesn't matter directly towards the number of skills that you have to choose of. It is your proficiency in the respective skill line that makes the difference. You could, e.g., hit level cap and still have only three class skills available if you didn't slot class skills and thereby didn't level those skill lines.

At level 10, provided that you distributed your skill points evenly among the three class skill lines and one weapon skill line, you should be somewhere about level 12 in those lines. If that is correct, you will have two skills available in each skill line, plus one or two of the passives. Keep using the skills, keep using the weapon, then you will unlock more skills soon.

Fair enough thank you