For the OP. Live sound is an industry that has little interest in certificates and a lot of interest in experience. Also, no one starts in the industry as a sound tech, you could work years before you get anywhere near the mixing desk hands on.
Little that can be done while we are in covid lockdown. But once live music starts to happen again the best step you could take is to join a local crew, either for a large venue, or for a company that provides local crew to a number of venues.
It's not glamorous, it's hard physical work, but if you stick with it you will get two very valuable rewards. The first is experience on working on lots of shows with set, backline, monitors, lights, PA, rigging. You will start off unloading and loading trucks, building sets/stages, and unpacking flight cases. As you do more shows and learn more, you will be trusted to help build and rig light and sound systems, and (as I did during my decade of local crew work) you will eventually be trusted to do a lot of work unsupervised.
And that brings me to the second reward; the reason I was trusted to work unsupervised was because the touring crews keep coming back to the same venues and get to know the guys who can be trusted to learn and do as they're told. And when they meet a local crew they will ask for guys they know who can do the job. These people become your contacts and your network. And what is unusual about this industry is that many PA and Lighting company Directors enjoy going out on the road. At one point I had the business cards of directors of two top Music Business trucking companies in my wallet, because I mentioned to a driver that I was thinking about getting a heavy goods vehicle licence, and on each occasion the driver was a company director who had seen me working his truck on many occasions.
The more I understand Music, the less good I get at it.