If you worked only with a provided harddisk-file, this implies for me that you created the VM yourself. The default network-setting for new VMs is "NAT" so you have to create a NAT-Rule, routing the host's port 22 to the VMsVM's port 22.
I don't know about MacOS, but under Linux, you'd have to use a port > 1024. I usually use ports starting with 10000 and the respective service-port. In your case, I'd make a mappingport-mapping of 10022 -> 22. For the hostentry in the "host"-sidecolumn I use 127.0.0.1 and for the guest-side 0.0.0.0 as addresses in.
You get to the hostmenu via "Right-column.click on VM" in VirtualBox Manager -> "Change" -> "Network"-tab -> "Port-Forwarding"