long press on where you want the info to go. Seems to work OK for me,

to copy text, just put your finger on a word and it should highlight, then you can drag the little tags to get more text, full sentences, paragraphs etc. a little menu should also come up at the top of the screen with some options including "copy"

then go to the place you want to paste and hold your finger in the reply box or whatever, a menu should appear with a paste option.

As I said above, sometimes sorta works. Usually, the marks disappear or jump around.

bad enough on a regular keyboard

You touch the screen on a word of text?

✌🏻