Why cant i zoom in anymore into a mesh? creating a scene in the beginning was easy because i could zoom in all i wanted in order to do model the mesh, but after i place more objects i reach a point where it is hard to move around in the model space because it would slow down to a stop, also i cant just rotate my view and zoom into an object. I was wondering if i can change this. I've seen that by pressing "." i can zoom into the mesh, yet i would like to know if theirs another way so that i wouldn't  have to do this every time. I've also tried changing the navigation auto depth on and off in preferences. (currently using Blender 2.8)
Hei

You can disable selection from all the things in scene. It will be easier to generally zoom in and out after this.