What blood tests should I ask for to diagnose fatigue?

I’ve been having trouble getting through a day without napping lately. It’s actually interfering with my life a lot, and I’m about to start my new job so I wish I had energy.

I have an appointment with my PCP in just over a week. I’ll mention my concerns to her and see what she recommends, but is there anything I should specifically make sure I get?

I’m thinking B vitamins and iron at least.