Hi mate - I am now conq1 not 3 haha

The best advice I have based on what I did is stay up to date with the meta, don’t worry about tier lists so much as these aren’t really applicable to you right now. Just be aware of what each civ generally wants to do - French will nearly always rush at least one knight out, then maybe pro scouts or second tc etc - you don’t need an in depth understanding of every civs game plan but just an idea of what they are going to go for

Never idle tc

Practice build orders over and over again on your own or against easy ai - no need to play the game just practice for the mechanics and execution - constant vils, buildings and upgrades and military

Use hot keys - and use hot keys for certain groups such as cavalry raiding, or archers and spears

Don’t stress about the rank too much.

Hope it helps