Questions from a virgin

I feel a bit silly asking these questions but I genuinely want to know. When eating a girl out can I get sick or get/cause an infection by getting any of her fluids in my mouth? I'm always really cautious about gettung sick and staying healthy because I have a weak immune system. I feel I would have no issue with oral if it weren't for the health concern? also as a lesbian how do you practice safe sex? is it necessary? Also.. is all lube edible or only specific kinds?