Is there a way to select multiple anchored images within a text frame? I am just wanting to scale down these 3 circles and am wanting to scale them simultaneously so that they are all the same. I am trying to shift+click but its not working.
No, it's not possible to select multiple anchored objects.
As it says in Adobe's help page on anchored objects:
Using the Selection tool, you can select only one anchored object at a time. Using the Type tool, you can select a range of text with multiple anchored object markers. When you select multiple anchor markers with the Type tool, you can change the position options for all the anchored objects at once.
Selecting with the type won't be helpful in your case as it won't allow you to scale the items.
A few workarounds
If the text frame only contains the anchored objects you want to scale or if all your text is tightly formatted. Scale the whole text frame and afterwards Clear Overrides for both the Object Style of the frame and for the Paragraphs Styles within the frame and drag the frame back to its original size.
If you want to setup a document where anchored objects can be scaled globally, you could look into using Object Styles. A group can be Pasted Into a square graphic/unassigned frame which is pasted into a text frame. That container frame can have its Frame Fitting Options set to Fit Content Proportionally and have its size set in Size and Position Options. That way you can resize all frames of that kind in one go.