I recommend to just stay away from anything mains voltage related for quite some time (maybe one or two years).
I find it quite surprising that a lot of beginners in electronics want to start with things like:
For example, a video might show the barebones way of controlling an ac powered light bulb with a relay from a microcontroller.
Just start with some breadboards and some small uC module that fits on a breadboard (forget that horrible "arduino" form factor). And then either use a lab power supply, batteries or wall warts. A (simple) lab power supply with adjustable current limit is a great start for powering your DIY electronics. The current limit is quite often the difference between letting out the magic smoke because of some faulty wiring, or just fixing the error and continuing.
For analog stuff. Start with the simple things. Get a NE555 to work, build a power supply with an LM317. Play around with some jelly bean opamps.
Also, do keep in mind that you will make mistakes and blow stuff up. From that perspective it's great to buy for example an assortment box with 600 transistors. (Which cost around EUR10). TO-92 transistors are great for breadboards, but when designing PCB's, I find SMT parts easier to work with.
There are also many beginners books for electronics, but I have not looked at them for many years. A simple approach is to just scrounge a bunch of them, start reading and throw it in the dump if you don't like that particular book and get on to the next. There is a lot of difference in quality of books, but there is also a lot of variation in people and the way they learn. Some prefer a hands on approach with examples, others prefer a more theoretical approach. Video's can be great for presenting a project and finding interesting stuff, but I usually find them a very bad source for learning. Video's are too passive for that. You have to do things yourself to learn and grow understanding.
Electronics is also a very diverse field. From power electronics to digital stuff. PCB design, soldering techniques, safety and reliability etc. Getting a DC motor to run with a battery and a switch is simple, but writing and debugging a FOC algorithm for a 3-phase BLDC motor from scratch can easily take up a few months of your (spare) time.