Im newbie in Ars of magica, ive got my first magic, how i enhance the damage?
well, something that isn't described and often missed is the changing of the casting modes
If you go into controls, there's a casting mode button, that toggles between your casting modes.
You can tell what mode you're in by the icon next to your mana bar, if it's a cresent shape it's diminished, and your spell will do less damage, but also cost less mana. Whilst if it's in a semi-circularish shape, you're in normal casting mode, and you'll do more damage but it will cost more mana to use too.
Physical damage spells don't actually do much damage, but they're also the cheapest to cast. You unlock other damage types later, and even later on you can add a damage modifier to make spells that do more damage.
Personally though, I would recommend going into the utility branch and getting the dig spell first off. That is extremely easy to spam, low mana cost, and will easily get you up to lvl 10 in a few minutes of training. And from there you have a few more skill points to play around with.