There is a stray kitten outside asking me for help. What should I do?

It looks diseased and starving. I put some food and water out but there are other strays around that will probably get to it first.

I don’t really want to touch it because it is oozing liquid from its face.

Should I grab it with a plastic bag or something and take it to… the humane society? Where? Will they charge me? I feel bad and don’t want to just ignore it.