hello .. i'm confused with these pronouns ( it ,this ,that)... e.g
i like it
i like this
u like that ...it's ok .. that's okay
could anybody tells me the all uses of IT ,This ,That ....
thanks

It would take pages and pages to explain the differences, and the uses of each.

Perhaps you could give two sentences using 'this' and 'that' and say why they confuse you.

this is an amazing.
that's an amazing .
it's an amazing.
whats the difference ?

Let’s make them into full sentences:

This is an amazing picture.
That is an amazing picture.

Now, in Grammar Monster, there is an introduction to 'this/that'. Read the information there, and let me know.

www.grammar-monster.com/glossary/demonstrative_pronoun.htm

got it .. thanks ..
can we say "its an amazing picture" ?

When we say, "its an amazing picture", we have used a contraction of 'it is',

We show that by writing:
it's an amazing picture

Notice that " it's " has an apostrophe.

" its " is what we use - just like, 'his, her" - to show possession:
The dog was wagging its tail.

There is more about this on Grammar Monster at :
apostrophe