Just discovered I have over 8K photos stored on my computer in My Photos. How do I delete groups not wanted?

Answer 1

Just right click on any photo or folder and click DELETE. If you wish to delete a bunch of contiguous photos. left click on the first, hold down SHIFT and click on the last, then right click on any one and click DELETE.

Answer 2

I just click on what I dont want and then delete. Once everything is in the trash I completley remove it from there. If you want to delete more than one at a time just hold down ctrl then click on each group you dont want then delete