Initial Connection Steps
To connect to a SharePoint site, you must receive an invitation via email from an owner of the site. The email will come from the person who manages the access to the SharePoint site. You can save the email for future reference if you need to reconnect and can't remember the link to the site. Alternatively, you could access Office 365 Apps via the Campus Single Sign-On (SSO) and after launching SharePoint, you can access sites that have been shared with you.
Clicking on the link in the email will take you to the CSULB SSO page which is located at https://sso.csulb.edu
Once you have successfully logged into SSO you will be redirected to the SharePoint Site. After logging in, you should immediately click on the Follow icon which looks like a star in the upper right section of the page:
If you don't do that, you may need to find the original email to find the link.
Reconnecting to the SharePoint Site
To reconnect to the SharePoint site, log in to SSO (https://sso.csulb.edu) and click on the Office365 chiclet. 
Once you are logged into Office365, you should see your list of Apps and an icon for SharePoint. 
After clicking on it, you can then select the SharePoint site you want to access from the left sidebar listed under following. You may also see another section called recent, which should also show you the sites you have accessed:
Search
You can also search for a particular site by using the search bar located in the upper left section of the web page (see screenshot below). Simply type in the name of the site you are looking for (in this case CED-TECH) and the system will return the sites (and files) that may match your search criteria. 