I did everything you said...
It is definitely about my experience level.
I did some minor enchantments, consuming experience points and now it's like this:
My experience is 6 and it doesn't allow me to do anything over level 6. I didn't know that...
Glad you got it figured out!
It can be hard to put oneself in the mindset of a beginner and understand exactly what they are misunderstanding.
Basically you need more XP levels to get better enchantments.
You can block some of the bookshelves , with torches or something in the inner ring around the enchanting table to get more options at low XP levels. (At high levels as well.)
And low level enchantments can be combined in an anvil to get higher level enchantments, 2 enchantments at the same level combine to an enchantment at the next level but that can be a trap since you can only use an anvil 6 (?) times on the same item (when combining items it's the one that's been anviled the most times that sets the limit) and that limit affects both combining enchantments and repairs, so if you go the combination route you'd want to get Mending on the item before you hit the limit.
Also the cost in XP levels goes up for each time through the anvil, so at some point it can be cheaper to make a new item than to use the last repair or two.