Error: Cannot find module './candy-machine-cli.ts'

I encountered the same issue as well. The trick here is to implement and get candy-machine working by using candy-machine-v2-cli.ts.

Candy Machine v1 is deprecated and it is v2 that you should use to create your candy machine.

The steps remain the same and you could try running the below command (which can be found with explanation here):-

ts-node ~/metaplex/js/packages/cli/src/candy-machine-v2-cli.ts upload \
    -e devnet \
    -k ~/.config/solana/devnet.json \
    -cp config.json \
    -c example \
    ./assets

Besides all this, I would recommend you read the docs on Candy Machine v2. It has covered things comprehensively.