There is a learning curve. If you jump straight into the 5 on 5 matches without some basics down it’s not much fun. Do some single player against bots. Then play coop against bots. Then do multiplayer gun game. Once you can win a round of gun game, IMO, you are ready for assault, uplink and escort.
The main thing is knowing maps and the radio. A team that uses the radio well and can call out locations will destroy a team of sharp shooting lone wolfs.
There are people who take it serious and those that are trying to figure things out. It’s all good. People will teach you things. Also the competitive lobbies are marked as such, so just avoid those.