​how to spend time after 9-5 learning extra stuff that have potentials ?

Currently I am working as Intelligent Transport System Engineer. My day to day involves, working with CCTV camera fault finding, Fibers , PLCs fault finding, various bigger or smaller project (technical) involvement in office, collaborating with network engineers and other vendors/contractors, variable speed sign and variable message sign fault finding or any other technologies that are inside the Tunnels. Similarly, jetfans, OMCS integration, incident detection system, fire systems, etc. I have Master degree in Electronics and Communication Engineering.

There are a lot of learning to be done in my work and it’s never ending.

My work is very flexible, and hence, I usually get 4-5 hours per day to work on anything besides my own work time table.

I am really confused what I should be using this hours and where should I be investing that hours. Only thing I can invest time is on anything that is Online (learning / work).

Before this, I had experience on Electronics Engineering in R & D ( Fault finding and Quality Assurance).

I can learn other stuffs such as CCNA courses (for network engineering) and upgrade my knowledge and change my space.

Or keep deep diving inside the technologies and knowledge what’s been going on at the moment. I can do what I am doing and learn CCNA or other any certified course. Work is very generous on

spending training on any thing. I have already done many Project Management, Digital Services course, plus Genetec (for CCTV) full course.

Or :

I start learning something else, which potential could get me to some side incomes (side hustles.)

Photography ( very interested and have gears) Website and web application designing agency ( interested, and have already talked with few mates from hometown to start this) Learn AI (Claude, etc ) and start learning something useful Digital Marketing Social media stuff creating using AI

This is to grow income, or grow some potentials to build something that goes long way, besides what I am doing.

5 hours per day is a lot of time I can invest in something useful, I think.

I would like to learn from others and want to hear any advice you can offer please.