How to get started with Wordpress CMS for freelancing


I have got a new job where I would be working with Wordpress CMS to manage company website. I am new to Wordpress but have an idea of how CMS works because I have been using Adobe experience manager(another CMS) in my previous company.

I wanted to understand from the technical point of view how I can leverage my newly found Wordpress expertise to get some Freelancing gigs part time. What technical skills I should have a grip on to be able to get started with freelancing? Like should I learn PHP or anything else?

I am pretty comfortable working with html/css/JS and a decent understanding of React. Have been using these to learn more about web dev in general.