you can easily obtain vote crates by voting for nypsi with $vote. you can also get crates from tasks, daily rewards, fishing, loot drops, premium rewards every friday night / saturday morning or the online shop.
you can get random items such as collectables and cars, but most notably being tools such as fishing rods, guns, pickaxes, other crates, boosters or scratch cards.
you can use the $use <name of crate> <amount> command to open specific number of a specific crate.