Well, the machine you’re on now doesn’t get security updates and hasn’t for some time, so you definitely need to upgrade as soon as you can, especially if this is for paid work. My suggestion is to grab a refurbished 2019 Intel Mac. That should last you a few more years.
once apple stops providing os updates for it (best guess is ~5 years), if you need to do Intel based support, buying a windows machine and running workstation will be your only option. They’ve now confirmed that they only provide security updates for the current and immediately previous versions, so you’ll have about a years notice when Intel is end of life.
as for the copy paste, one option (highly recommended) is to get on a supported version of fusion. You can buy a 13 license and support can downgrade the key for fusion 10. Just make sure you make a non Time Machine backup, with the vms shut down (not suspended) and all snapshots removed before upgrading.
