You can get leads in using the Contact Us page on your website. Visitors use the contact form on your website to leave questions and contact details. This automatically gives you a lead and can turn into an opportunity. Automating the lead/opportunity generation will improve your efficiency.
With the CRM app installed, you benefit from a ready-to-use contact form on your Odoo website that will generate leads/opportunities automatically.
To change to a specific sales channel, go to Website ‣ Configuration ‣ Settings. Under Communication you will find the Contact Form info.