Regarding Investment Banking I would start with a corporate finance textbok like the one from Vernimmen & Quiry or Berk & DeMarzo. For M&A / investment banking go with the textbook from Rosenbaum.
With regards to financial modelling, Beninga & Damodaran can be useful references (both textbooks and spreadsheets found on their websites). Then you’ve got the financial modelling training like Break Into Wall Street / Wall Street Prep / Wall Street Training (i like BIWS for the sector packages). I think Macabacus is a very useful reference (both add-in and the learning resources). There are also free things you can find in blogs and Youtube channels if you have got time (which I personnally don’t) of some M&A analysts or ex-analysts who like to show off their skills.
That is all I can think of.
Regarding Excel you can find loads of resources, training, certifications, etc. I could not advise which ones to pick.
Financial management is very hard thing as everything needs a lot of planning and analysis. These suggestions for investment banking and financial modeling learning resources would be very helpful. I am reading many blogs these days to learn basics such as what is equity, capital investments and forex etc.