SQL novice needs a little help

Hi Ben, I am doing some work in SQL for the first time. I have got myself ok with some of the basics through YouTube, but I need a little help just to make sure I’m going the right path with a particular urgent task I need to do. Basically I’m dealing with a large data set that I need to condense (ie reduce the number of rows) so that a system which uses this data uses less processing time. I know conceptually how to do this (was able to effectively achieve it in a PivotTable in Excel). I also want the new condensed/aggregated data to appear in a new table, rather than just running a temporary query from an existing table. Would you be able to help with this? I’ve never used a service like this before, but would be good to have a brief call if easier or if I’m not clear? Also ideally looking to get some example SQL code that I can then replicate using the same logic. I don’t think this would take long, guess no more than an hour of your time?

I’ve also uploaded an example of what I mean with the bottom table being what I am trying to replicate. Also to add, I’m also looking for a formula that will aggregate DATETIME values to be the end of the year (see this example uses Birthday).

Thanks in advance

Sam