I'll answer this from my perspective, which is that of someone who started out in a tech support role 30-odd years ago, and now run engineering operations teams in data centres.

One of the best teachers is experience, but it's hard to get that experience until someone gives you a chance. Support desk/helpdesk are great entry-level jobs that'll get you started. To help with your self-study for something like this (and if you have the means) consider starting a small homelab and growing from there.

Perhaps you can find a cheap managed network switch - either new or second-hand - that lets you start playing with VLANs. Maybe an SBC or two (Raspberry Pi, Orange Pi, etc) so you can start to experiment with Linux, and hosting servers. That'll open the door to playing with other things down the track - Docker, nginx, etc.

The point is, when interviewing for entry level roles, I (and many hiring managers I know) will usually ask if a candidate runs a home network. By no means does that mean a candidate without one doesn't get due consideration but, when I see someone's eyes (and passion) light up when talking about their homelab, I know I'm onto someone who will grow and develop well in the role I'm hiring for.

If this sounds like a path you want to go down, a couple of useful communities where you can get info and advice on homelabbing are !selfhosted@lemmy.world and !homelab@lemmy.ml.