I'm kind of the same way. I just hit 30 and fear getting into the ranked action. When I am playing, I am always going to try my best, but I hate that there is always someone around to yell and complain at me no matter what I do. For example, in my last game, (my 2nd of 10 of the pre-ranking games) I played bottom lane support with Braum. I ended up 4/0/14 (game was surrendered at 22min). Though for the last ~10 minutes of the game, my bottom adc partner, Graves, was yelling at me for kill stealing. None of my kills I would consider a steal. The one he wouldn't let go of was for good reason. He was 2v1 ambushed as I was catching up to him. I leaped to a minion, just to get somewhat near and ult'ed into the group to get the double knockup, and got one of the kills. Graves cleaned up the other and laid into me the rest of the match. "Your pokes suck.... Kill stealer...learn to support....noob".
In my head, I know this person is just acting immature and foolish, but it drives me crazy having to deal with it . I spend the entire match angry and wanting to lash back out. At the end of the game, I realize the last few minutes weren't even fun because of his harassing.
My advice, definitely get into some Pvp..its so much more fun than bot games. You are going to run into these types of players, you just have to ignore them. Just reply something simple that doesn't provoke them further "It's an unranked, pre-level 30 match. I'm trying my best" for example. (Then report them at the end of the game)
For gameplay advice, I would say, watch some youtube video's of high caliber Sona's playing. Check some sites like mobafire to get build advice for her as well.
As for the 1k RP, you could send me a mystery skin ha. Really though, I would save it and try to get something you like on sale. At this point you don't need anything, just keep exploring to find your favorite characters.