How to get answers?

Can I just schedule an appointment with a doctor and ask them to run a blood test to see if I have celiac? I have had worsening symptoms for months and never thought that it could be celiac until just recently. The thing is though, I don’t have a primary care doctor. Should I find one and ask them or find a specialist? Is it okay to just ask them to run the test or should I tell them my symptoms and let them figure it out