Clip question?

What kind of clips can I use to put on the end of my hair to pull the curl out? Do you clip them at the main bottom of the hair? :?
I'm confused about this and want to buy some clips but I want to be able to get them at the drugstore. How heavy are they supposed to be?

2c, 3a and 3b combined. I think anyway
Love Activate poo, Jessicurl too shea and aloeba as a leave in, Curls spiral cream(old version) and milkshake!!