Just tried setting it up, pretty simple assuming you're comfortable with Linux.

You need MySQL/MariaDB, PHP >= 5.5.9 (see composer.json, require section for version requirements - worked with 7.1.x for me), node/npm, and composer (typically installed from getcomposer.org)

Otherwise, directions at https://github.com/monicahq/monica#setup-the-project work with one exception: I'm not familiar with laravel in particular, but I had to do some funkyness with the the .env file:

Replace APP_KEY=SomeRandomString with a valid key, like this random one I found on the internet: APP_KEY=base64:i7QndWbN33zY1x013Yw2cju9KQsxpT/1nnf8/3ziZ+U=

Then run php artisan key:generate to get a new one.

(Set DB credentials in .env as well)

Finally, php artisan serve to fire up the dev server (uses php's builtin server)