Not the best but im having fun learning! 
Update for color. Had an issue where materials just dont link to other objects anymore. It worked a couple times then stopped randomly and it will sometimes apply to one other object or none at all. Got her done with the “copy material to selected” option
Looks like some clean modeling
Thank you!
When I saw the animation I thought it was a building with rooms.
If you connect multiple objects to the same material, then yes, when changing the material options it works on all objects.
This happens also when you LINKED DUPLICATE objects (alt d), they inherit the same material.
If you just copy an object (shift d) the same material is used. But can be easliy replaced.
When you say you thought it was a building with rooms, do you mean i could change something to make it more bookshelf like? the dimensions are a little different but it looks pretty similar to my bookshelf i thought.
Also im not sure what you are explaining as far as linked duplicates.My question wasnt why objects with the same material all change when I change the material,thats self explanmitory. But as it is now the ctrl+L ->materials doesn’t work on any object.
Welcome to this site.
Good first model.
When linking a material from another that has the material you want on the others, the one you want to copy from must be the last selected, making it the ‘active’ one. It will be the brighter yellow highlighting colour rather than the darker orange of the others.
@NP5 I have tried having it be first selected and last selected, neither works unfortunately
Clip for reference. Im not sure what im doing wrong honestly, I went back to watch the video and I do the exact steps only for nothing to happen at all. think you guys can point me in the right direction? I found a work around, but its irking me
Bit fast and hard to see at that scale but I can’t make it fail as it does for you. Using either method. I had never used the little dropdown on the far right before either. lol Strictly a Ctrl L materials person.
Test it in a new file.
sorry about that 
idk why i thought it could go full screen haha. I like the ctrl L menu a lot, but the lil drop down was the only option other than individually applying hundreds of objects with materials >.< no thank you lol. Just tried it in a fresh file and still no dice. maybe a newer version of blender? do oyu know of a setting that changes how the ctrl L menu works?
Well it is possible a version change but it would be odd as it is long standing and in with all the other linking things.
Well options are reset factory defaults, file; defaults.
Or get a different version of Blender. If you get the portable versions you can run many versions on the same computer.
There is the little mesh triangle below the material changing dropdown you use, it has two settings, data and object, normally on data. I tried out switching to object but it made no different to my tests. Grasping at straws here. lol.
at least you know which straws to grasp! second day on the program 
it doesnt work with factory settings either, guess I was the lucky one to get an unknown bug. will try getting 2.83
Try 2,92 that is what I am using.
lil update: doesn’t work on 2.83, nor 2.92. It worked once, but I think only when I changed the data/object drop down, but literally only worked once and I couldn’t replicate it. Still not working at this point and I’m just going to reluctantly use the drop down work around for now sadly.
That is so weird. It must be something local to your computer, no idea what
though.
Perhaps others will have ideas.
Do you know of maybe a cache of some sort that I could clear? maybe its some cached process that defaults anytime I try using the link feature?
Another student had also problems with a hot-key.
The culprit was NVIDEA video card setting, also using the same hotkeys.
See: ALT + R not working
Not that I know of, when a new file fails the operation then I doubt it would be related.
The hotkey itself does what it needs to and brings up the link menu, its the link feature that isnt working. I dont use the hotkeys in nvidea
