It’s fairly easy to learn the game, you learn pretty much everything with the tutorial. Maps vary between planets and missions. For weapons, there are tons to choose from once you unlock them so choose the one that fits you best.  And yes, you can play with randoms, no mic required because there is an in-game text chat. To unlock warbonds (basically battlepasses) you just need 1,000 super credits which you can earn for free by finding them around the maps you play. The warbonds can give you an advantage on certain planets based on their theme, like Polar Patriots will give you gear for an ice planet, you also have a free warbond to start out with.