You did alright. I believe that one game was a mismatch, but don't worry about it. Play only to learn. You can still learn from that game and that should be your goal in the early levels. Whether it was a win or not doesn't matter.
You were CSing well in lane. At one point I recall you were ahead to the extent it cancelled out, in your lane, LeBlanc's roam. So good job on that. You kept shoving into turret which was good for two reasons 1. The Leblanc wasn't good at CSing and 2. It's Leblanc. I don't know if you knew that,and were trying to do this deliberately but it was good either way.
That leads into my second note: I don't know if you are a new player so you don't know what all the champions do yet, because you were slow to react to opponents abilities. If you don't know all the champions, no problem. That's just an experience issue.
I believe you need to use your pings more. When you were roaming top and ulted, Nautilus was not in a position to follow up immediately. I would estimate that was because he was not aware of the situation and I don't think you pinged it to communicate it. It worked out well in the end, but if Nautilus was in position it would have been so much cleaner, and he wouldn't have been so close to escape. That is what is good about Nautilus top, he brings so much CC that he is great to gank for, no matter what kind of champion you are.
Speaking of your ult: An important thing to learn to do is to keep in mind everything your champion can do and how that relates to the situation as it changes.
Like there were missed opportunities for your ultimate. When your team found Xin Zhao alone in the jungle, you missed out on ulting him because then you would have caught him out without his Flash. Now I know you likely wouldn't know that he didn't have Flash, but if you did Ult then you would have him trapped. He wouldn't have been able to get to his team and get away like he did.
You also sat on gold. I don't know if you just kinda gave up at that (which would be kinda understandable) or what but you shouldn't be doing that.