Yes, you can have your Google Ads up and running in under an hour, and you can be seeing clicks and traffic within that time too. But to start seeing those proper results, with consistent sales and a solid return on ad spend (ROAS), it can take a few weeks or even months.
For a realistic approach, with regular optimisation tweaks, expect something in the region of 4-8 weeks to start really seeing a solid return on ad spend (ROAS).