Help with modifying budget templates: charts, sparkline, and linked tabs

Hi there. I'm not very Excel savvy, and I'm trying to modify a preexisting excel budget template to better represent my expenses. I've attached the workbook, which should help clarify exactly what I'm talking about.

My primary concern is that I can't figure out how to have my charts at the top of the "Money Tracker" tab change to reflect the month I'm viewing (using the slider). I broke this function when I heavily modified the tables. Can someone provide details on how to fix this?

Secondly, I'm not sure how the Sparklines work, but I do like this feature of the template. It's very visually appealing, and gives me a good at-a-glance idea of the history of my expenses. How can I fix these so they capture data from every month?

Finally, is it possible to link the data between the tabs? For instance, I'd like to record my categorized expenses/income only on the "Budget Planner" tab each month, and have it auto-fill to the "Money Tracker" and "Budget History" tabs for the correct month. However, I don't want them to be permanently linked, because I'll be wiping that first tab at the start of each new month and filling in new information (the historical data will be stored on that third tab.) Is this possible? I don't mind altering the formula each month, as long as I know how.

In advance, THANK YOU for reading and EXTRA THANK YOU to anyone who replies.