This essentially just adds a new way to make custom components.
To add/edit custom components, you can go to data.ts/data.js in scripts/Custom Components/Custom Item Components/ and scripts/Custom Components/Custom Block Components/.
Yes, you'll still need components like minecraft:tick and minecraft:random_tick for block events.
There are example block and item files along with custom components. To see all options even if you're writing in js, look at the TS interface files.
This was made to help people that don't know how to script update their addons.
TS files are in ./scripts/, JS files are in ./BP/scripts/