Best Order to Upgrade & Update a 15in mid 2015 MacBook Pro

I’d like to upgrade the ssd & update to the most current os on a mid 2015 mcb pro-2.2ghz, 16gb ram, 250gb storage. Is there an optimal order that I should follow-is it better to upgrade the ssd first & then update the os, etc? Also, any tips/tricks, recs on ssds would greatly appreciated!

Author: @KVSreads