It's nice to be with you

“It’s nice to be with you” OR “It’s nice being with you”

first off let me tell you that I know that the second one is “informal” but I need more details!!!

Best regards

The second isn’t necessarily any more ‘informal’ than the first.

There’s just a slight change in emphasis. The first emphasises the ‘being with’ the second emphasises the ‘you’.
There’s very little (if any) difference in everyday usage.

Thanks dear
I really like you my best friend!!