No, you got one hero, your allies got one hero each. In 5v5 there are three lanes, in 3v3 there are just two. In each lane you got towers to guard your base, and in the middle is the place without towers. After a minute or so in game each base will spawn minions to walk on each lane, of course they will go fight in the middle of each lane. If you are in the middle lane in 5v5 or the top lane in 3v3 you are usually playing alone on that lane. Since playing alone gives you more exp. While others are playing together in pairs in the other lanes. You all try to defeat the minions, kill the enemy champions, destroy their towers, switch lane and help each others, etc.
In between the lanes are beasts that belongs to neither of the teams, and are indicated on the minimap with skulls. Some give bonuses when you kill them and some just give exp and cash when you kill them.
In between the lanes are beasts that belongs to neither of the teams, and are indicated on the minimap with skulls. Some give bonuses when you kill them and some just give exp and cash when you kill them.