with talkback, the procedure to copy text is as follows:
1: find an edit box with what you want to copy.
2: swipe up and right for the local context menu
3: if you prefer the circle method, swipe up for cursor control, activate it by lifting your finger, then down to get to select all, then lift your finger. Note that you can select and copy specific stuff from the edit box by activating start selection mode, changing granularities to match what you want to copy, like characters, words, etc and swiping left and right to increase and decrease the scope of what you're copying.
4: Once you selected something, wether with select all or specific selection, bring up the local context menu, go to cursor control and hit either cut or copy, depending on what you want to do, just like on a pc/mac/chromebook.
5: go to where you want to stick it and hit paste from the local context menu and you're good.
6: if showing context menus as lists, it's the same, but instead of swiping around a pizza pie of items, you would double tap on options, just like you would in a standard android ListView.
For shine, I stopped using it a while ago, but to change granularities, go to the command panel and select the desired granularity under I think move. I don't mean to bash it, considering for two public releases, the quality and app support were at least comparable to talkback which in my opinion is pretty damn impressive, but I had a load of issues with it, for instance on lolypop, the back, home and overview thingies couldn't be tapped on, you had to do that annoying two finger thingy to use them, and second of all, those permissions! Is this a screen reader or chinese/nsa spyware? What would a screen reader need to call and reroute phone calls and read your contacts for? Also, with shine, you could copy text from the screen, which I will admit is quite badass, but you can't paste, go to paste, you get "Shine keyboard needs to be selected for application", that's all fine and good, until you find no mension of shine keyboard as a possible input method or even anywhere in the play store/dev's sight.
hth