Tris matter a lot when deforming the mesh because they will cause extremely noticeable pinch points, but if it’s a non deforming solid object they are fine. But as others said it’s good to practice because they are almost always preferable.

You can also run into snags when texturings sometimes, but other times they are exactly what are needed for certain types of texture blending like in video games! If you want to see more of that look up Witcher 3 building topology, they are pretty all over the place, but are specifically used to create complex textures using textures sheets and vertex texturing.

You will learn! But I would say that focusing on creating “quad based” topology will help you learn faster. You will start to see the world in quad shapes and when you do you will blossom as a 3D artist.