There are now menus for Portal64 including save files and control

Latest ROM Download
https://github.com/lambertjamesd/portal64/releases/tag/v0.10.0

N64 Homebrew Resources
https://discord.gg/WqFgNWf
https://n64.dev/#community 

If you want to code using the official N64 SDK
https://crashoveride95.github.io/n64hbrew/modernsdk/index.html

lIf you want to use an open source SDK
https://libdragon.dev/