Sharing and working on mixes

A friend of mine and I just recently bought Cubase. He purchased his a couple of months before I did. The idea was to have the same program to record and mix songs and to be able to go back and forth sharing and mixing the songs on our separate computers. We have not yet figured a simple way (or any way) to share the mixes yet. Can you help me or point me to a tutorial?
His system is PC, cubase 9.5 artist.
Mine is Mac, cubase 10 artist. Also I bought Halion 6
Also what would I need to do if I wanted to transfer sounds to a studio to mix in a different environment, and they are not using cubase? Also note I am using some Halion six sounds when recording.

First you need to make separate folders for every project.
Then it’s easy to copy a project to a cloud sharing service like Dropbox.
Don’t work directly from the cloud folder or you will end up with corruption at some point, as many have reported happening.

To deliver a project to a studio for mixing, you would often render each track down to audio (wav), from the beginning of the song to the end, even if there only is one drum hit on that track.
Then when the studio imports the tracks to whatever DAW they use, they will be in time as they start at the same time.

Also if one of you has plug-ins or VSTi’s that the other doesn’t have (like Halion 6) you might want to lean away from using those on Projects you are passing back and forth just to make sure everything will sound the same on the 2 systems.

That said, if you have a Halion 6 sound you want to use, you can always render the part to audio like peakae describes. That way your friend can hear that line even without owning Halion 6.

Have you considered VST Transit that is built into Cubase?

https://www.steinberg.net/en/products/vst/vst_transit.html

With reasonable network bandwidth and some care you should be able to use that fairly effectively.
I had hoped to use it to meet people with whom I could collaborate but the social networking side fo the system is lacking from my location . In your case you have a known contact so that won’t be an issue. Technically it supports what you need.

Thank you. This is all very helpful. I never even heard of vst transit. Going to dive into that tonight!