In Procreate ‘Colour Drop’ is the equivalent of the paint bucket tool in Photoshop. It’s a ‘hidden’ tool activated by a drag and drop from the current colour swatch, which is always there in the top right-hand corner of the Procreate drawing screen.
Compared to pen on paper, I’m struggling to control my line when drawing on an iPad, even with a Paperlike screen protector (although after three or four months that has worn fairly smooth). For the lettering I tried Procreate’s method where you pause at the end of a line, curve or ellipse. Procreate works out what you were trying to draw and turns it into a smooth, editable vector version.
My unaided line is too wobbly, the vector version to smooth but I’m sure I’ll hit on a ‘Goldilocks Zone’ version which will be just right!