Thirty five days in and I feel I have learned and understand more of using Unity than I did trying to learn by myself over the last year. Case in point, adding power ups to my game.
First we need to left click and drag the sprite we want to use as our power up into the inspector. Then we should rename it to something we will recognize, in this instance Triple_Shot_Powerup.
Now we should resize it to fit in better with our game, then add a rigidbody2D component and a collider2D component. Make sure gravity on the rigidbody is set to 0, also make the collider a trigger. Now we can drag and drop this powerup into our prefabs folder.
Now we just need to add a script to the prefab to control what we want it to do. We can also add a spawn routine to our spawn manager, so that the power up will spawn every few seconds.
As stated at the start, it is starting to feel like a real video game.