Ready Made Lined Curtains Is It Difficult To Add Linings To Existing Ready Made Curtains? Also Can I Just Add Black Outlinings Alone?

Is it difficult to add linings to existing ready made curtains? Also can I just add black outlinings alone? - ready made lined curtains

It is a nice pair of readymade curtains on Ebay that would look great in my room, but are not aligned. Is it really difficult to add the trim to the curtains, which have already formed? I have never sewn, this is something I could do or could have been much cost for a seamstress to have for me. If this is an important task, then it is worth me buying curtains. It's just that there are 2 pairs fit perfectly into my window.

Also, if you want the curtains to have a power that I feed and fodder normal or power outage, you can easily fit blackout lining.

Thank you for your help.