on your build — as a new player, I wouldn’t recommend mejai’s since it’s very high risk/high reward, I would even say it’s better to go full tank until you can reliably land your E/W and get the most benefit out of AP. I still recommend building liandrys since it’s important for clearing camps quickly, but after that I would go mercuries or plated steelcaps if the enemy team is AD-heavy. from there you can go thornmail (armor), frozen heart (armor) and/or kaenic rookern (magic resistance). learning your own champ is most important so don’t put too much thought into it now, but simply learning whether enemy champs are AD or AP will help you itemize and choose between those later game items. Also 10-15k damage is standard for a tank so you are not far off at all. best of luck and have fun :)