Every website/portfolio should have an "about" or "about me" page. The page may not be called "About me". In some cases, people choose to use the landing page as their about me page. Regardless of where it is on your site, you should have a page that contains a brief bio of who you are. It should include a headshot photo, as this helps people ensure they are in the correct place (e.g. if you meet someone at a conference and then search for them, the photo helps ensure you get the right person). One reason to not include a photo is if a photo might cause you to be discriminated against.
For an example, see my about me page at https://edtechbooks.org/-VLYD.
Here are some readings with advice on what makes (or doesn't make) a good About Me page:
Tip: To help personalize your About Me page, I recommend including a video introduction.