[jitendrac]

Good wordpress developers are in great demand. If you find the right clients, you can earn above average the market standards.

About your skills, There are many new trends in tech in last decade. Since you have worked withe web, I will suggest you to start with HTML5, CSS3 and Javascript's new features which you may already be knowing.

Start learning server side js. Node.js is bit confusing if you are old folks but see some tutorials and follow them, start with light framework like Express and make small app. The benefit of node.js is you can share many modules at both server and client sides if needed[though beware of it].

Alternatively if you want to stick to PHP, the easiest will be to start with codeigniter and when you feel likes getting grip move to Laravel. Laravel is in great demand. Learn to use it with docker.