I'm a beginner and I would like to know how あまり is used.
This won't be all the uses of あまり but it should give you some idea how it is used :)
As a noun:
It can be used simply as a noun meaning "the rest"; "the remainder".
He bought books with what was left of his pay.
The remains of the meal were thrown away.
It can also be used as a grammar point
～（の）あまり（に）～ showing the result of having too strong an emotion. It connects to nouns with
の or just comes straight after verbs.
I was too shocked to do anything at that time.
She was so happy that she danced for joy.
worry so much about the future that you neglect the present
As a na-adjective:
Expresses that something is extreme; too much; beyond expectations
make too many mistakes
look too good to eat
As an adverb:
Comes before the verb as an adverb expressing that somebody is doing something too much, more than they should.
If you study too much you'll ruin your health
With a negative, expresses "not very much". This usage in particular is very common and often becomes
あんま in casual speech.
Not very good
Not so cute
Don't eat very much
As a suffix:
Comes after a counter to express that something is more than the amount
More than 100 employees
More than five years ago
Example sentences and information from: