Slider pic

How do I make the slider pic smaller? It is very large in comparison to the rest of my presentation page and doesn’t look right. Also, is there a way to create a custom pic just for the slider pics? It pulls the first pic fr a post to put in the slider but the pic doesn’t look good but if I change the blog post pic, then it would look wrong on the blog post.

Also, how do I add a sixth social network? I’ve run out!
Thank you,