Alrighty it’s been some years since I’ve played but a lot of the answers here don’t get the full picture.

Everyone talking about toxicity isn’t wrong, but that’s more often at the high level/ranked levels of play. It can happen in random lobbies of course, but it’s far less frequent. What I suggest here is cautiously eyeing the mute all chat. Sometimes it can be helpful to type messages, sometimes people say awful, awful things. From the former, sometimes you can learn. From the latter, it’s pointless to even bother to try.

I would suggest keeping in game chat turned off.

Use online build guides - the meta of the game changes pretty consistently based on updates and nerfs to the characters. Your best bet for consistency is picking one character to learn - I suggest going by what feels most fun abilities wise.

Another thing here to keep in mind is there are roles in this game, top is often tanky, mid is often AP heavy, and bottom is often ADC and healer. (may have changed since I played).

Until about level 10 - tanks will be on their own a lot at the beginning, mostly just trying to survive being team-attacked (a gank) and planning with the team when to come in to help.

Mid keeps an eye on top and bottom lane, mostly keeping the other mid-laner occupied. Once in a while you go up top to 2v1 or down bottom to 3v1. Sometimes people come to you, but I wouldn’t expect it.

Bottom has to be watchful for ganks, and you need to work with your healer to make sure you get minion kills. You two are pretty much on your own as the only paired teammates, however occasionally a teammate will come down to help push.

During all of this, the first 9 levels or so (may be less, again it’s been a while) you will be placing vision items on the ground to avoid being ganked and setting up the items for your late game build. During this You’ll want to avoid being killed and major risks. You’ll just be following what the build guides say, but it can be helpful to learn what aspects of what you are affecting. In brief, there is magic damage (AP) and physical damage (AD). The ADC class mostly uses AD, but there are characters who can use either/both. The other surrounding stats matter in other ways, but those two are the main focus.

So for example, your ADC character picks items that increase their speed, attack speed, and damage. But now the enemy has an item that mitigates physical attack damage, so you can decide to buy an item that ignores a % of armor.

These items eventually are bought into bigger versions of it, so the item you start with sets you down a path, the other items you choose supplementing what you’re missing.

Around level 10 the individual dynamic begins to fade and you begin to group together as a team. During team fights you’ll want to stay together with your team, really the best thing overall is to be there when it happens. Around the next 5 levels and depending on the circumstances, your team may go find the monsters who give buffs - there’s the dragon which gives the whole team money, and the baron which gives the whole team a buff. These you have to go a little out of the way for, but they can be very strong strategic choices. You can also witness the enemy team fighting these, and attempt to steal the kill for it, giving your team the benefits instead.

Finally, I would say get comfortable with one character of each role. You can’t always be _____, sometimes people just pick first. Other than that, just do your best to have fun with your son. Don’t worry about min/maxing if it isn’t fun, don’t worry about other teammates complaining if you are legitimately trying, and for the love of all things don’t spend money on this game - it will only unlock characters you can unlock for free or give you visual aesthetic skins that don’t actually affect anything. They don’t need your support and you don’t need their offerings.