Two basic rules: M1 Macs run Arm-native code when it’s available, but won’t mix ARM-native and Intel code in the same process. Here are the details.
zsh
How can you run an app in a language different to that set for your system? Why doesn’t that work for command tools? And how difficult can a tool make controlling its environment?
Do you know how to customise the zsh shell now standard in Catalina? Here’s an excellent book which covers it in detail – and curious choice in 10.15.
Links to official Apple support articles, and important 3rd party pages. How to run Aperture in 10.15, where to get old versions of macOS, and much more.