There are a few Vue2 kits available, but I assume you are just monitoring the mains and not each circuit. Looks like you have the mains clamps installed fine. Yes, the blue and white wires go to the bus bar where all the white (neutral) wires are landed. As your panel is almost full, you have a few options for powering the Vue2. The installation manual talks about several ways, such as connecting to existing dual breaker or using only a single breaker to power (it looks like you have 1 spot).
Personally, for a couple of your circuits which aren’t GFCI, I would buy a tandem breaker so you can reclaim a spot in your panel. After getting a free spot back in the middle left (from the tandem breaker), move the lower left GFCI breaker up over to the freed up position. Then you should have 2 free spots at the lower left. Install a 15A or 20A dual breaker for the Emporia in the those lower left two free spots. See a link below for what the tandem breaker looks like (two breakers that fit in one slot) – but be sure to get the proper type for your style breakers and panel.
https://www.acehardware.com/departments/lighting-and-electrical/circuit-breakers-fuses-and-panels/circuit-breakers/31486?x429=true&gclid=CjwKCAjwjJmIBhA4EiwAQdCbxkL3EO_xEDKL4E75kHEUodaX6qFt5U_AmQMP3V3flFG0YKvSs3dsTRoCJZIQAvD_BwE&gclsrc=aw.ds
Of course, only do any of this if you are comfortable working in the breaker panel, and can turn off individual circuits or mains for safety during the circuit changes.
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