We have been using azure with PS for well over 5 years now.  hosting the IIS server, azure container apps, azure sql, etc. for our powerserver based application.

You say that your application is for oracle but the database is currently sql server?  Do you mean your application is already running using sql server?

That change will probably be the biggest.  convert it to sql server first.   Azure sql isn't really much different than a sql server running in a partial containment.  No cross database joins or anything that accesses master database.  master is a sql server specific database, oracle does not have that concept.

moving to PS requires IIS setup and it should be setup to use JWT or similar auth if this is going to be publicly available (c# things).  the PB code doesn't change much to get it to run.  Your login processing might change a lot, but it just depends.   The IIS and other server setups stuff may be the hardest if you haven't done it before.  Additional considerations are the region where the servers are hosted and whether you want to front end your webapis using the azure frontdoor which may provide a performance boost to the webapis.

In terms of getting it to run well/fast, that may require additional changes to your application, but it depends on your application and how it was written.