Is it possible to find and choose a casino that will provide the best bonus package upon registration? I don't understand how I can settle on one option when each platform has its own bonuses.

Or just try different casinos. Nobody restricts you from registering on different platforms. For my first time, I chose 100 euro no deposit bonus casino, since this option seemed to me the most profitable at that time. And these bonuses, even taking into account the wagering, which turned out to be not the easiest, helped me earn my first money.