Can someone explain how mana work, how do I get more, how much do I have and what items or stats should I aim for

[saberlost]

As title, I just started, it says stuff cost 50 mana, but it does not say how much mana I have, ( it feels like I can spam all my abilities) . Or how I gain mana.

Also I cannot find my charater sheet in the game. I have just gotten the skill tree, but where do I see what wepons I have and what gear I have?

[Cooptimus Prime]

The gear page opens up a little later, after you get a new piece of gear. That page will have your stats on it as well. Getting more magic is usually through the skill tree, there'll be nodes that will give either a +X or a +% to stats. Sounds like you're still pretty early in the game, just keep playing and more will open up.