So I'm currently around lv 20 and I'm still being matched with people who still don't even know the concept of last hitting

I recently wanted to try jungling with rammus but I have one huge worry
It's not if I'm good enough
Someone has to take a solo lane in a land where 2 top is meta
Should I just forget about worrying and jungle, trusting my team mates will be able to handle a 2v1 and farm decently?

Gank top lane. A lot.

Also it depends. You should ask if they're going to be okay play 1v2 top and who they plan on using. I used to use Nunu at lower levels to 1v2 top. Easy health, farm, and if they try to tower dive pop that ult.

It's only level 20 games. Feel free to jungle. You're making the solo a better player by making him 1 v 2 anyways.

Instead of playing blind normals, play draft normals. People have a tighter sense of the meta.

You could also jungle on a blind normal game but you should ask first, of course.

If people at your 'normal' elo are playing the 2-1-2 no jungle meta, it won't make much of a difference if you jungle. Just make sure that whatever lane is 1v2 gets the most attention. A good jungle Rammus can easily swoop in, taunt the squishy autoattacker, W, give their teammate free hits, and walk away with 2 assists, 2 kills. or 1 of each.

Well, it'll make a little difference, your solo lane should be able to level faster, and you'll have the element of surprise.

Absolutely this. It will prepare you for ranked play very quickly and help you develop with a variety of characters.

Can't agree more. Draft is really the way to go if you want to get used to playing the meta and ranked games.

I don't jungle, I have no concept of how to do it properly. A lot of people that jungle in blinds, on the times it does happen, are NEVER there when you need them. I'm only level 23 and I can't tell you how many times I've died because I thought a jungler was coming to help top but then was just going to get golems or something, while I'm 2v1 or 3v1.
Just pay attention to the map and if someone asks for help, get there.