I've been considering opening up commissions, but there's so many sites to showcase an art portfolio that I don't know which to choose. Does anyone have good advice on this? If you can give as much detail I'd appreciate it.

A lot of friends I know in real life and artists I've seen on here primarily seem to use tumblr as an art journal site to showcase their art.

But if you're looking to create your own art portfolio website a la a professional art portfolio website then, the one I know off the top of my head, wix, I believe is free. I've known artists who use wordpress as well, but that requires payment, I believe.

Weebly offers free websites with templates where you can just upload images of your art! And you can have a contact page for people to contact you via email for commissions.

I definitely can say that if you are just starting out, any website hosting service online will be sufficient. I have seen many artists use Artstation or Portfoliobox which both seem very nice. If you feel like you need a change of pace and want to some distance from any centralized company hosting all your work, definitely make your own site. That is, of course, a lot more ambitious, but can be great if it fits your art. Platforms like mmm.page, glitch.com or even neocities are the most perfect places for this if you don't have too much experience or money, I find and give you all of the control you need!