If you're coming in from Civ V/VI, then you'll definitely need to readjust your game. This is much more macro focused compared to V/VI.
A few tips I can think of:
- Food is king. It's the singular reason why plains suck in this iteration of Civ, as you trade one food for one hammer, which is much less useful in the opening stage of the game. Always settle food-rich spots first. As to why...
- Bronze Working is a god tier tech in IV. Why? Because it enables Slavery, which allows you to convert food into hammers and due to the way production works, you wont be wasting hammers even if you use it on a unit, as the overflow will carry over into the next thing in queue.
- Know the few key techs in the tree. Bronze Working is one of those, but others like Feudalism (enables Longbows, super helpful defensively), the religious techs which allows you to found a religion (the practical ones the player can shoot for is usually Monotheism, Code of Law or Philosophy). Liberalism for free tech, Optics to explore oceans, Monarchy to enable the civic, etc.
- If you're new, pick powerful, easy to understand leader traits like Financial, Creative, or Expansive first. UU and UBs of nations are typically not very game changing but as a rule of thumb, the earlier they are available, the more of a chance they will make a difference in game (also the reason why Germany's or America's UU are considered trash because they're available so late).
At the end of the day though, don't be afraid to drop the difficulty to noble first, which I feel is the equivalent of Prince in the later games. It is also the difficulty which neither you or the AI are given any advantages, so its also the most fair in that respect. Starting from Prince, the AI starts getting bonuses to beakers and hammers, and outright gets bonus units as you play on Emperor and above.