How do I get Better at League

Currently in this season, I got placed into Silver II on my first account ranked, the problem is after a bit of ranked ( about 50 games) I have decayed into Silver 3 with 20 lp. I can cs decent though it can always get better, but I don't think that's the problem. I ward when I am pushed up so I can prevent ganks. I just not quite sure how to harass though and close out games efficiently. I main top so should I roam a lot and try to snowball lane since I am unable to win mine? When I am behind and try farming I just get constantly zoned and end up really far behind. Is there any way I can fix this?