Ugh... Kennel cough isn't fun... There's not much you can do 'besides wait it out, then get her vaccinated! As for the hot spot on her tummy, you can find soothing lotions and such OTC at pet stores, or you can get stuff from your vet that will heal and taste like crap so she won't keep chewing. If she's scratching, you may need to wrap it up.

The lump may or may not be anything major. The best thing to do is to get a vet to take a look and do a biopsy. It may just be a simple growth that is easily removed, or it could be malignant. Either way, a vet is the best way to go.