Hi,
you should visit this web-site https://travel.state.gov/content/travel/en/us-visas/immigrate/the-immigrant-visa-process/step-10-prepare-for-the-interview/medical-examination-faqs.html#:~:text=The medical examination will include,abdomen%2C lymph nodes and skin.
After you receive an interview letter, you should go to website of us embassy in your country, find the page with certified MDs in your country and make an appointment. Physician will check your vaccination record, take an Xray of lungs (TB text), blood test. Bring all vaccination record with you (no english translation is required). If you need some additional shots, you will get it during your exam. I have not had my exam yet but planning to get hep B shot (I lost my old record) in a advance.