Is it ok to get a tooth extraction before a root canal filling?

? unclear. I'm not clear on what your question is or why you are asking it? If a tooth is deemed hopeless it needs to be extracted. Many teeth can be saved with rct if restorable ; the long term prognosis is good. Once the tooth is extracted it's gone! and no other treatment is possible other than replacing it. It sounds like you need to discuss your situation with your own dentist as well as your options.
Root canal. It is better to save your tooth if possible than to, have it extracted. Both procedures will eliminate the infection. Have the root canal and safe your tooth if you can.
Don't understand . If you are talking about the same tooth then, no. Once a patient decides on extraction that is definitive. If you are talking about multiple teeth and you have decided to extract one tooth and root canal another, would be up to you and the doctor to decide the order of treatment.
NO. Root canal treatment is used to remove an infection. A second way to remove the same infection is by removing the tooth. Both treatments result in the same outcome however in one case you still have a tooth. You may have one or the other but not both. See your dentist to determine which is right for you.