Ok figured it out.
First step, is to open your router and add your raspberry pi to the port forwarding. This is easy enough, you will want to use the internal IP of you pi, and open port 22 to tcp. you can usually access your router settings via http://192.168.0.1/ in your browser, providing you are wired directly into the router and not using wifi to connect.
Once this is done you will need the external ip. I found it by going on to my retropie under "retroarch netplay".
You will need this external ip to login from the internet.
this site has the steps on creating a new user:
https://humanwhocodes.com/snippets/2021/03/create-user-linux-ssh-key/
Once done you can open putty from any pc connected to the internet and ssh into your pi by using the external ip.
Expose your pi to the internet at your own risk.