You're already a strong Hollow if you know how to get Mask Cracks in Type Soul. When you become a Hollow, you're a fairly weak creature, according to Bleach lore. You don't stay that way, though, and considering how Hollows progress, you'll first become a Menos.
[Type Soul] NEW Fastest Adjucha Mask CRACK FARM! (Best Spawns!)
From here you continue to grow stronger by becoming Adjuchas and eventually becoming Vastolorde. However, while it sounds easy, you need to get Type Soul mask cracks in order for that to happen. If you’re not sure how that would work, here’s what you need to do:
You will need to find and defeat other Adjuchas to farm Mask Cracks. Depending on your luck, the Adjuchas can drop up to 5 masks upon defeat. The best place to hunt Adjuchas is in Hueco Mundo, although they will occasionally spawn in Karakura town.
When looking for them, try to look for places like the swamp pool or corners of the map where Bawabawa boss spawns. These places have a chance to spawn tougher enemies like Adjuchas. Other than that, a general trick you can use is to go to a higher area and see if you can spot them.