What is best mage spec for pve now? A bit confused what to choose?
My normal question would be: Best for what? Dungeons? Raids? World content? and then refer the questioner to raider.io and warcraftlogs.com
But you seem to be in the lower levels, where those considerations don’t apply. Starter account?
At level 20, any spec will do fine. I prefer Frost. I have heard some things about Arcane becoming overpowered with some scaling gflitches and clever use of Arcane Charges, buy I haven’t played at low level this expansion.
I would suggest you try all three, and see which you enjoy most, and which performs best for you.
As stated it really depends on the kind of PvE you want to do. At low level I believe Arcane is absolutely busted, crazy DPS with their spells. At higher level I believe it becomes the most difficult of the three specializations to play, and I think all three specializations perform fairly well overall, with it more coming down to what you prefer.
I think Fire has the most mobility, Frost has the most survivability, and Arcane has the most DPS potential but has to hard cast the most and has lesser mobility/survivability compared to the other two specializations.