Updated with more tutorials!:
Are you planning on using a Pi headless? Be sure to check out the following tutorials first to make sure that your understanding of the various methods and protocols often used is up to speed.
First things first you need to connect your Pi to a network that you’ll be accessing it from, note that you don’t strictly require internet access here. There’s also the potential to set up port forwarding to access your Pi from anywhere on the wider network of the internet if configured on your router, but be sure to identify any potential vulnerabilities this could create within your network before trying to set that up.
If you’re looking just to access the bash terminal I’d recommend taking a look at using SSH (Secure-Shell) which is usually run on port 22 (and is by default after enabling it in raspi-config) there are a few clients that you can use for this which include a GUI (PuTTY is a personal preference for windows machines) or you can simply use the bash terminal as described on How-To Geek
If you want to remote desktop to the Pi I’d recommend using VNC, the Raspberry Pi Foundation covers this brilliantly in the link below:
If you’re looking to host an FTP (File Transfer Protocol) server on your Pi, there’s also functionalities to enable that. You’ll likely want to use FileZilla as a client application but there are a few options out there depending on what you need it for.
Let us know if you have any issues with setup and we’ll do our best to help out!
Have fun with your new Pi! Feel free to share any projects you’ve done with a headless setup here!