Hi, I think you can start from this page: https://developer.salesforce.com/page/Integration Here you can find a dedicated document: https://developer.salesforce.com/docs/atlas.en-us.integration_patterns_and_practices.meta/integration_patterns_and_practices/ You can also search for tutorial video on youtube, especially on the Salesforce Developer profile.
I think you can start from this page: https://developer.salesforce.com/page/Integration
Here you can find a dedicated document: https://developer.salesforce.com/docs/atlas.en-us.integration_patterns_and_practices.meta/integration_patterns_and_practices/
You can also search for tutorial video on youtube, especially on the Salesforce Developer profile.