Hey! I am trying to make a donation page on big cartel for my website

I am making my website on Big cartel and I think I am using the neat theme. I would really like to somehow add a donation page where they can donate money to children’s hospitals and missions trips/missionary. But the only thing is that Idk what to do to make it! Also, I would like to add a page like Pinterest where if they are part of my memebership they can post ideas and I would like a page to show all of my posts on Instagram Pinterest and Facebook! Like I said though I have no clue how to!