1. shove lane for level 2 first (assuming all xp is soaked up you'll hit level 2 after the 3 melee minions on the 2nd wave) and go all in with the level advantage.

2. nidalee ganked bot when your adc and their bot lane was very low, you backed off of the low health alistar, this would've given you a kill if you had continued chasing, jinx wasn't a threat since she had no mana and wasn't level 6 yet.

3. you pressured mid when bottom lane was pushing and it was still very early in the game, when you and your adc go to pressure mid make sure bottom lane is pushing towards their tier 2 turret so your turret doesn't get split pushed down. pushing like that also forces someone on their team, usually their adc to go and stop that creep wave from going to their tower, if they don't stop it their tower will take damage and they'll lose lots of cs, or it'll even go down. pushing the minion wave before you rotate to mid leaves you and your adc to freely roam or rotate and get an objective with a number advantage allowing you to fight 3v2 etc. because of nobody doing this you lost two towers which could've been prevented.

4. locket or righteous glory would've been a better rush than randuin's because of how much magic damage they have. also consider picking up a mikael's against nasus because of his wither.

captain's enchantment is good but i wouldn't rush it.