what is best way to pick up excel proficiency and learn new formlas

Practice is probably the biggest.

Resources that I referenced frequently when I was learning:

1) You can think of a spreadsheet as a "function based" programming language. Early on, I spent a lot of time reviewing the available functions and becoming familiar with those I would use: https://support.microsoft.com/en-us/...1-63f26a86c0eb The sheer size of the list of functions is intimidating, so figure out the kind of programming you expect to be doing and become familiar with functions related to what you are doing.

2) References are a big part of programming in a spreadsheet, so you need to become proficient at using references. Absolute and relative referencing is especially important: https://support.microsoft.com/en-us/...es_in_formulas

3) Number formatting is usually useful, so one of my most frequently referenced help files was: https://support.microsoft.com/en-us/...rs=en-us&ad=us

4) Finally, sometimes the best way to store data in a spreadsheet is not the most visually appealing. Especially if you are going to make use of pivot tables, filters, and certain functions (like SUMIFS()), you will want to store you data in a nice, "flat", database style to make summary and analysis of the data easier.

Check out problems/question on here, make yourself proficient with solutions provided - then try to find other ways to solve the question.