You'll need to use an app such as Calendly, YouCanBookMe, Acuity, etc. Then you have to connect your online calendar to the scheduling tool. Most software integrates with Google Calendar. You'll need to check the integrations available if you use a different calendar program. You'll set up the appointment slots that you want to make available by day of the week. Then, you'll configure the settings for your scheduling form according to how you want it to work. Most appointment scheduling software is straightforward to set up.