Lol...I just went and peeked. That was a pretty mild freak out! In answer to your question, ideally you're looking for blue and green numbers in the middle of the cycle. I just realized that won't make sense until you have a spreadsheet....Blue numbers are between 100-199, and green numbers are 50-99 for a human meter. (Sorry, I'm not sure on the alphatrak since I don't have one - but it's on the spreadsheet) Getting to those numbers takes some time, so try to be patient. It's often said here that this is a marathon, not a sprint. I have to remind myself of that almost every day.
Most of the time if you test before +2, the number will be higher than the pre-shot because food makes the number go up. Because of that, I don't test before +2, and usually not before +3, but there are lots of people who do test even in those first hours. Just know if you do, and get a higher number, that that's normal. Generally cats on prozinc hit the nadir (lowest point) somewhere between +4 and +6, so you tested at a great time tonight. It will take a little while to figure out when Yoshi hits nadir - it's possible to be earlier or later than that, but for now you can guess sometime in that range.
Many of us give our cats food all day long (except for the two hours before a shot). If Yoshi seems hungry, it's fine to give him more food as long as it's low-carb. Especially before they're regulated, many kitties need some extra food, so unless Yoshi is overweight, you can generally feed as much as he wants.