Low cost vet

This weekend my friend found a ~5 wk old kitten under the hood of her car. I’ve taken them in in the meantime. I’ve done a bit of googling, but was hoping someone could point me in the right direction for some low cost vet services, spay/neuter, bloodwork etc. This is SUCH a sweet kitten who is dying to play with my other two cats but I don’t want to let them interact before I’m certain they’re not FIV+ etc. Thanks so much in advance!