My dog looks to have a bite on her ear it's been sore for…

It could be allergies or an infection. Take your pet to the vet if you can. If not, shave the surrounding fur with clippers like this picture. Apply a small amount of Hydrocortisone/Benadryl ointment and an antibiotic ointment such as Neosporin to the sore once every 12 hours for 7 days. These drugs are safe as long as your pet does not lick it and ingest a significant amount. So only use a small amount.  Or you could use an antiseptic spray with chlorhexidine. Call your local pet store and ask if they have something like it. Also, give your dog 1mg of Benadryl per pound once every 12 hours. Finally, put an e collar (cone) on your pet to prevent licking. You can get one from your local pet store too. If that doesn’t help, let me know or go to a vet. Do you have any questions about what I said?

Swelling in the ear usually indicates an Aural Hematoma. This happens from trauma to the ear from head shaking or getting bit on the ear by another dog. It will go away on its own after 2 weeks but there will be scar tissue and the ear will look slightly deformed. It can look like a cauliflower ear in humans. The only way to avoid this is to get surgery done at the vet. The vet will place a drain in the ear for 10 days. Your dog will leak a small amount of blood during that time but it can be bandaged to keep it clean. There is no way for you to drain it at home. If you do, it will fill right back up within a few minutes.