Welcome new players, here is a little advise to help get u started.
1. Buy a mech, trial mechs aren't customizeable. Taurus, Shaydan and Fiddler are good starter mechs due to low costs.
2. Get a third weapon. It is usually best to have a weapon for close, medium and long range.
3. Make sure to assign your Tech Tree points as you get them.
4. Purchase upgrades.