Are you planning on DIY for refinishing? If not you talk to the person doing the work. I looks old so could be fir or pine I can't be certain

Probably oak, but agree it could be something more surprising depending on where you live. You should be able to keep it natural once the damage has been sanded off, but they should also be able to give you ideas of how stains would look.

You can refinish it less yellow. Bona Red Out anyone? (houzz.com)

Red out isn’t Amber Out. It also will not stop the normal changing colors of wood photo-oxidation.

Then you can use Bona Natural Seal and Traffic HD for the best light finish with less yellowing.