I would start here emoncms/readme.md at master · emoncms/emoncms · GitHub it gives you instructions for installing emoncms from scratch on an existing setup. I did this about 9 months ago and I only remember one issue (although I can’t remember what).
{edit} I installed the OS onto a HDD rather than to an SD card. The SD card errors are probably due to too many write cycles. The HDD was simply and old one out of an end of life laptop in a cheap case from Amazon. There is a script to move the OS to an HDD somewhere.