Everybody will probably recommend a bunch of books or MOOCs with varying degrees of practicality but if you want to learn in the sense of building some sort of intuition, then just buy:

- A large breadboard

- A battery holder

- An online kit with an assortment of passive components (resistors, capacitors, inductors)

- A cheap USB oscilloscope

Some of these kits even include things like FETs, opamps, 555 timers etc. Which really stretches what you can build.

Then just look online for circuits that you find interesting, build them and probe them (with the oscilloscope). The closer you get to building something you find useful the more engaging the experience will be.