Add the Button module (category General) from + Add New Module. Its edit panel has Button Title, Button URL, Main color and Constrast color (the button's background and text colors – note the label is spelled "Constrast" in the current interface), Rounded Corners, Fluid (full width), Alignment, and Margin/Padding. It is a lightweight standalone button block – use it when you just need a call-to-action link between sections rather than a full Hero or CTA module.