To sign up for an opportunity in the Volunteer Tracker you have the option to click on the "Opportunities Listing" tile, "Opportunities//Opportunities Listing" tab or the "Opportunities Calendar" tile:

Once on the Opportunities Listing tile, you will see several different opportunities (if available) that you can sign up for. 

You have the option to filter by location, activity, or by opportunities dates by using the filter boxes.  if you volunteer at multiple schools you can narrow the search down by using the Location drop down box to select the school :

Make sure that you have selected "Needed" as the requirement so you will see the list of opportunities that volunteers are needed for:

 After you have added all of the info that you wish to filter for you must click the "Filter/Search" button: 

If no opportunities show up for you, you may want to edit your search filters and then search again. Some schools enter opportunity info and some schools do not so this will make a difference in your search. It will be best to contact the volunteer coordinator for your location on whether or not opportunities will be created for your location(s).

If the list of opportunities show up for you, this is how you will sign up for it - you can  click on the name of the opportunity or the Volunteers Needed button(this example is the Band Concert) :

Now that you have clicked to open the opportunity you will see a new page with all of the opportunity information - remember, this is just an example so your school's opportunity will have different information listed :

Notice the green button that says "Sign Me Up" - that is what you need to click on to sign up for this particular opportunity. 

Once you click to sign up you will then see a new screen that shows you that you have now been signed up for the opportunity. You can click the blue Edit button(located at the bottom of the page) to make any comments or changes - that screen looks like this :