Will my 2015 MBP be able slowed down? will Acrobat work? Will Excel and Word?

I have a MBP Retina mid2015 running 10.12.6; I use AcrobatPro, Microsoft Office and Quicken. The question is how much will this upgrade slow down this computer?

The second question is will I lose access to older documents?

I plan to buy a new computer and wonder if it would be wiser to keep this computer with 10.12.6 and purchase upgraded software for the new computer??