There is no Homestead directory to cd into. You specify the folders you want to share in your Homestead.yaml file.
Check out your Homestead.yaml file by typing homestead edit. I'll paste mine as an example:
---
ip: "192.168.10.10"
memory: 2048
cpus: 1
authorize: ~/.ssh/id_rsa.pub
keys:
- ~/.ssh/id_rsa
folders:
- map: ~/Code
to: /home/vagrant/Code
sites:
- map: save-the-date.dev
to: /home/vagrant/Code/save-the-date/public
databases:
- save_the_date
variables:
- key: APP_ENV
value: local
Do you see the folders option? That's where you specify shared folders. map: is on your local machine; to: is on the vagrant box. Also, notice the sites option. That maps URL's to folders on your vagrant box. Homestead will automatically set up the site with an Nginx instance. Just make sure to add whatever name you specify in the map: to your /etc/hosts file so you can access it. The IP address you will use in your hosts file is at the top of the Homestead.yaml file.
You can find all of this and more in the docs, like @sitesense mentioned. Check them out for sure. They're great!