Okay so I’ve solved this with a lot of tinkering. First of all my Sage theme has a lot of code that references the function the_field() because I use the Advanced Custom Fields plugin. And of course when trellis installed wordpress on my droplet, it did not install any plugins. So my template kept calling the_field() and without the ACF plugin it returned errors like crazy ! So I tried to install the plugin but I could not add any plugins from my wp admin ! Which drove me nuts until I realized that I need to install them using composer (composer require wpackagist-plugin/advanced-custom-fileds) which worked like a charm ! So now my site is working, and I’ve learnt so much about bedrock and trellis 
Hopefully my errors and comments can help someone in the future !