It's a good game but any advice any of us give you won't make any sense.
For example...
Bottom lane is for ADC and support characters so make sure you match up with one or the other if you go bottom.
Top lane is subject to random attacks from the Jungler known as "ganks". You need to make sure to ward the river and the bush and keep an eye on your minimap to avoid ganks.
Both Red and Blue buffs (Lizards/Golems) spawn at
1:55 and respawn 5 minutes after EVERY creature in their camp is killed. Dragon spawns at
2:30 and respawns 6 minutes after dying. Baron spawns at
15:00 and respawns 7 minutes after dying. Make sure to ward these so you can control them.
If Yi gets fed, run.
Now, did any of that make any sense to you? Of course not. So what you need to do is what I said. Stick with Ashe for now, learn how to last-hit. That's all the advice you need right now.