And good idea about spectating a match to get the flow of things. That probably will reduce 50% of friction.
1. have at least played some pve, the "scenerios" are good for forcing you to learn a lot of the basics. if you literally dont know how to do basic interacting with the game there is nothing that the other players in the "noob" lobby can help you with. you will struggle they will struggle no one will have fun. pvp is just an objectively bad way to learn the game. don't even try to play pvp until you are at 2 or even 3 "chev". its a complex game with lots of mechanics, its going to take time to get the basics down. 2. watching replays/specing is helpful. so are some of the yt basics guides. find someone elses build and strategy and try to copy it. you can get to a pretty high os just by doing that. if you get beat bad in a round go watch your own replay. see what the other guy did. copy it next time. 3. remember that its an apm taxed kinda game, players will spend their apm trying to help you, but they wont have time to say things nicely. its not them trying to be mad or rude usually, they just dont have time to write you a novel. use the inbetween matches chat to ask for details. assume good intent on in game chat most of the time. 4. remember that os is literally just a number, it really doesn't mean anything. but finding lobbies with similar os to you helps. like even though there are lots of lobbies with like 30+os who will allow your 10-15 os noob self in its not the right match for you. find lobbies with like 25ish os cap. or no more than 10-15 os higher than your current rank. even better ones that are "unranked" but they seem more rare. 5. the rotato suggestion i saw on another thread is good but also the glitters/supreme with the consistent roles is also kinda nice. its much easier to find lobbies and follow replays and stuff, pick the same lane and watch how a few different people play it and copy what looks like it works as best you can.