Styling is what separates an amateur page from a professional one.
Typography
In the Style tab of a heading or a text block, set the font, the size, the weight and the line height. Golden rule: two fonts maximum across the whole site (one for headings, one for body text).
Colours
Define a consistent palette: one primary colour, one secondary colour, and a few shades of grey for text. Elementor lets you save global colours that you can reuse everywhere.
Tip: use the global styles (Site Settings) to define fonts and colours once. The whole site then stays consistent.