Currently we are hosting a .net core app running mongodb as a database on location in our phisical servers, what services would i need to get it running in azure?
Is a virtual machine, with added hard disk space enough?
Why are there dedicated products on marketpalce for example for "sql servers" if you can just install them in the virtual machine?
You should go for a PaaS model because it is cheapest and you have alot of features easy to use out of the box just with a few clicks. You delegate responsibilities to Microsoft to monitor your resources, maintenance, OS, networking, Security and Hardware.
If you want an IaaS approach i would recommend to use a D+ Series Virtual Machine.