Vitamin(s) for fatigue, mental clarity, general health?

I’m 27F, and I struggle immensely with being tired literally all the time… I don’t know what “well rested” means. I’m a pretty active runner, but I have a desk job during the day, and I often feel just exhausted and mentally cloudy. I don’t currently take any vitamins, so I was wondering what a good intro regimen would be to focus on energy, mental clarity, and ofc general health?

I don’t have preferences regarding multivitamin vs. multiple specific supplements or delivery mechanism (pill, gummy, etc.), but I’d like to not break the bank.

I have not had the bloodwork done for myself to determine if low iron is a factor, but both my mom & sister have been diagnosed with anemia, and I’m always cold (especially in hands and feet), so something with low-dose iron is intriguing to me. I’m a little trepidatious to go with a full dose of an iron supplement without getting a medical opinion, but open to thoughts and opinions.

Thanks!