New player tips?

I've still in my first few games , I've had really good groups that seemed to get that I'd only played online a couple times. I spent a long while in bot matches getting used to timing and farming and last hits and using items properly. But yesterday I played an unranked game where everyone else on my team had thousands of wins and commends, I couldn't keep up, I had a lot of issues and they kept trying to get me to do more than I was capable of as a pos 3 with three matches under my belt . We lost with 20 kills more than them at like 54 min. Im not sure where I need to improve or if it was just a bad match up, as its probably still trying to calibrate where I should be placed . Any advice or should I just keep playing even if I'm losing and making better players mad?