Barbara A Lolli

I have an iPad Pro 13"-and when I try to refine a selection affinity photo locks up...Also, is there a airbrush tool? I wish there was a search when you are trying to do something and can't find a right tool. I keep watching you tube video's to find something rather simple to do and it sure would be wonderful to have a search or even a place here to search things you want to do. Does that make any sense? Thanks and love your software Barbara