If you find this site helpful, consider helping me learn blender and posting on this site with my Patreon Page.  

I made this image by following this tutorial.

I used this tutorial here, 

Beginner

He briefly explains the modifiers in 2.8.

Cool uses for several modifers.

Constraints

Beginner

This person has some great ideas on how to use constraints to keep an object to a path, rig a piston, rig a jet exhaust,  He uses the snap to curser shift s keyboard shortcut.  He has some parts which don't constrain properly, and he shows you how to fix those issues.  

Beginner

Intermediate

This person from decoded has all the basics of making a room.  He explains how get the camera settings  from a thirdparty plugin, and how to make the room, furniture, and lighting.  If you do this tutorial you should be able to make a very nice room.