Thanks for your question.
I would recommend going through the following documents to get started:
- This article provides best practice guidance for building applications and services on Azure Service Fabric: Azure Service Fabric application design best practices
- Using Service Fabric to decompose monolithic applications
- Tutorial: Deploy a .NET application in a Windows container to Azure Service Fabric
- ASP.NET Core in Azure Service Fabric Reliable Services
- There is another Q&A thread which will give you an idea about what points to consider while migrating monolith into service fabric
Let me know if you have any questions or need additional help after going through the documentation.