Best excel resources for getting better with large amounts of data and scalable logic?

I need to practice and improve the logic around how I structure models with large amounts of disorganized data, particularly when drilling down into customer cohort data. Can I get some recommendations? 

I didn't come from an IB background, more the BD side of Corp Dev, so my modeling skills aren't where they should be. I'm able to find workarounds to get the right answer a decent amount of the time in the first attempt but my work tends to difficult to audit and adding new components to a model can cause breaks in other areas which I have to go back and patch. I've taken the basic modeling courses from WallStreetPrep and WSO so I can do any of the general DCF/LBO work easily, but none of those really did much to prepare me for a huge data dump of historical customer/product data going back 5-10 years. I need to get better with organizing it all so I'm not causing other members of my team to get hit with a time crunch because I'm having to go back and fix things. Got my first real taste of a DD process over the last week and my lack of excel fluidity caused several very late nights putting unneeded stress on my team which makes me feel horrible, don't want it to happen again.