
You are able to take part in the Events (both in-game and Community ones), complete Objectives and Achievements, join Tournaments, move through the Progress Path, and stuff! Besides, there are always affordable Offers, and Mech Arena Store https://store.plarium.com/en/mech-arena/ 🛒
Two additional small tips:
1. Keep a stash of some resources available at all times. This includes acoins and credits of course, but also silver crates, gold crates and fortune keys. These saved resources can come in handy for events that reward opening or using them, increasing your chances of winning some additional resources from those events.
2. In the beginning at least, don't rank up lower tier mechs, except for maybe one or two exceptions. Those acoins saved will have a better use later in the game as you progress.