New in blender create models ue4

Hello im a new user in Blender and i start to know some basics of the modeling.

What my future plans are is to import some models in the Unreal Engine.

What are the basic rules when you create a model who’s going to the Unreal Engine?

One of things i keep asking myself is,

When you create a table you have 4 legs and a top.
Do i need to delete the upper faces of the legs when i snap it to the top of the table. (So the legs have 5 faces)
Or do i just snap the legs to the top of the table when the legs still have 6 faces.

And how do you snap the legs to the top?

Its all very basic but those are the things i cant find an answer to.

General rule is if the player isn’t gonna see it, it doesn’t need to be modeled.

In the case of the table, it doesn’t really matter. Most modern games use 10-30 thousand polygons for most models. 4 extra polygons per table isn’t going to matter much.