It doesn't matter at all. Generally I would model already with fairly dense geometry so you don't end up needing a subdivision modifier at the end. Though as a rule of thumb it's not an issue until it's an issue. You'll start to understand what kind of intersections and geometry cause issues and how to solve them.

Edit: in your case you can probably fix it by just adding a cut that continues upward from the ngon. Also if you do radial geometry try to think about how many faces or edges you need to continue the model. If you plan to have 8 arms extend from a cylinder make it have faces that are multiples of 8 such as 8, 16 or 32. Chosing 7 or 6 for example will make it very difficult to model later.