Comment by mlsu
For this, what takes a while is to just tinker and fry components several times. Get a breadboard, get several sensors, try to design something and iterate on your design. Plan to fry sensors and IC's. Also helps to read some basic electrical theory and know what the role of different components are.
The way I got proficient is with hobbyist PCB design. What helped me is starting with schematics and datasheets and planning to finish with an assembled board. I started designing PCB's and having them assembled with JLCPCB (quite cheap: $20 or so for a run of 5 boards; $120-$150 fully assembled). I fried 2 boards before the 3rd rev booted up, then from there it's optimization. I consider the $200/mo or so in PCBA, whether boards work or not, to be my "EE education" -- cost efficient compared to university fees! And $200 is sort of like the "exam," it's costly enough to make me really think twice about component selection/placement/etc.
Not saying that's the approach you want to take because that might be hardcore / not someplace you want to get to. But I spent a long long time really wondering how electricity really works and like why you need capacitors, inductors, op-amps, etc. It never made sense to me until I created my own schematic, chose my own parts, and understood why I chose the parts I did and connected them the way I did.
This just reinforces the fact that it's inaccessible. There's no way I'm literally throwing $200 a month in the trash on a hobby.