DON'T HIT THINGS WITH A MALLET BEFORE YOU UNDERSTAND THEM.

You're watching videos for the wrong kind of crankset. If you had a two-piece crankset like a Shimano Hollowtech II crankset or BB30, then yes, that would be the case. The crankset's spindle would be part of the drive-side crank arm, along with the chainrings. But you don't have a two-piece crankset.

You have an SR SunTour Hexon cartridge bottom bracket & three-piece crankset. On a three-piece crankset, the spindle is a separate part from each crank arm. The drive-side crank arm removes just like the one you've already removed, and the chainrings will come off with the crank arm. The spindle is an integral part of the bottom bracket; if you smack it with a hammer, you're only smashing your bearings.

Once you have both crank arms removed, you can then remove your bottom bracket if necessary. To remove it, you'll need a splined bottom bracket tool like a Park Tool BBT-22 or BBT-32 and a wrench to turn it.

The SR SunTour Hexon system is basically like a common square taper cartridge bottom bracket, except the spindle has six faces instead of four.

They may look like outboard bearings (in such a small pic), but check out the shape of the spindle or the cutouts in the crank arm. They're hexagonal. It's SR SunTour's proprietary 'Hexon' setup.