You can research a color theory topic and learn about color psychology, combinations, contrasts, etc. However, we often don't have much time for in-depth research.
Here are a few quick tips to get you started
👉Browse through other websites, look for inspiration on sites like dribbble.com and www.awwwards.com and see what direction you want to go.
👉Decide if you want a light or dark website.
👉Choose a background color - this is the dominant color on your website
👉Choose a text color that contrasts well with the background and is easy to read
👉Choose an accent color to highlight your buttons and links
Luckily, many online resources can help you come up with colors for your website
📌https://colorhunt.co/ - a great resource with ready-made color palettes. Browse through different combinations until you find something that suits your taste
📌https://mycolor.space/ - enter a basic color, e.g. your background, and get many different color combinations that go together
📌https://coolors.co/image-picker - upload the photo you want to use on a website and get colors that match it.