Did the original doctor do any tests? In some cases, Parkinson's is so obvious that no testing is needed, but if it is unclear whether or not symptoms come from PD, things like an MRI to rule out stroke or a DaTscan to measure dopamine levels may be necessary. There is also a skin test that will measure certain proteins that indicate Parkinsonism. If you don't trust the first diagnosis, then ask the new doctor whether they feel that testing is appropriate.

If they feel that your symptoms are clearly Parkinson's, they will probably start you on carbidopa-levodopa. Your response to that (or lack of response) can be confirmation without needing more tests.

He's not your best friend. He's your Dr. Just tell him you want the best care there is with most education and experience. Good luck

Go to a movement disorder specialist.