I highly recommend using Pixelfed. It looks really nice, is easy to use, is FOSS, decentralised and federated, and is a really positive space. It's designed as a sort of Instagram replacement but whereas Instagram is used as a 'social media' advertising platform, Pixelfed is all art and photography. I actually find it to be one of the only genuinely enjoyable and uplifting parts of the internet at the moment and have discovered loads of art through it that I love and am inspired by. Have a look at some user profiles on a few instances to find one that looks like how you want to present your portfolio before signing up to one, as there may some variety between instances.
If you don't mind doing a bit more work, it's also not too difficult to set up a wordpress website on a cheap VPS using YUNOhost.
For ease and goodness I think Pixelfed is unbeatable though :)