Five Civilization 6 Tips for Beginners
1) Be aware of the 'show city details' button. This has many uses. First of all it summarizes how your city is doing, and also gives tips on how to improve your growth, housing and amenities. Second of all it teaches you a lot about the mechanics of the game, as it lays its calculations out for you in quite an easy to understand way. For example, it will tell you that your growth goes down with 50%, even though you have enough housing...what causes this? Well, if you only have one housing more than civilians, you already get a penalty. Without this summary it would be hard to figure out those things.
2) Make sure to know what pillaging does, especially in relation to farms and fishing boats. Normally, you can pillage districts and improvements for a bonus to e.g. gold or science. However, if you pillage a farm, you heal up a unit. This can be extremely strong when fighting close to a foreign city, as you improve your staying power by a lot.
3) If you are on the receiving pillaging side, you can repair the pillaged structures. However, there are different ways to repair different pillaged things. Improvements can be repaired with builders. Put them in the same hex, and click on the wrench icon. This costs a turn, but does not take a 'build charge'. Districts and buildings cannot be repaired with builders, but have to be repaired from the construction menu in your city. This means that it can cost you multiple turns of repairing instead of constructing new things in your city.
4) Take very good care when founding a new city, to make sure the citizens have access to water. If you build a city without water in its area, your maximum amount of citizens (housing) starts off at 2. If you have access to salt water (coast), the city will have 3 housing. If you have access to fresh water (river, oasis, lake), you will have 5 water. This can be improved by the aquaduct building. However, this building has quite some requirements. It needs to build adjacent to a river, lake, oasis or mountain AND be adjacent to your city. If you already have access to fresh water it gives you +2 housing. However, if you don't have access to water yet and put it next to a mountain, you'll have 6 housing, which is a big improvement. Watch the video to see how NOT to make a city (footage of my first game).
5) If you build a district over terrain with a specific feature such as a rainforest, this rainforest will be removed. Therefore, before you build the district, you can use a builder to 'remove feature', which will give you some resources before you build the district. If you build the district without doing this, you will not get those resources. This does however consume a 'charge' of the builder, but in general I'd say it's worth it, barring some exceptions.