how long does it take for a website to show up on google?

It all depends on what work you have done to prepare the website. Google will not make your website show up in search engines unless they know about it. Once they know about it, you need to make sure your website has been designed correctly so that they can read it. As a general rule, make sure you have a sitemap created and have submitted it to Google search Console. From here, the feedback you get in the console will help you identify any issues that might be impacting your rankings. It should normally take a few days for Google to index the site and have it appear in search results. It may not appear as high in the results as you might expect though.