The below links provides basic guidance for migration:
https://www.veracitysolutions.com/blog/on-prem-to-azure-a-guide-to-cloud-migration
sqlwizard.blog/2020/03/05/database-migration-from-on-prem-to-azure-sql/
Azure indeed provides multiple options like Azure SQL , SQL MI, Synapse etc.
Based on your current scenario, ask the below questions:
- Does your current system have cross database queries or linked servers ? If yes, then SQL MI
- Do you want to incorporate all in 1 database , if yes what is the size and complexity of transformations :for synapse
etc