Probably 90% or more of cyclist do not ever upgrade their drivetrain. There is really no point to upgrading for the "experience" and you are going to gain very, very little in performance. Just ride the bike, learn how to keep it properly maintained and learn what you need as far as gearing, fitting of the bike to you, pedals, saddles, etc. Then when you really need a better bike you can upgrade the whole thing and sell the (well-maintained) currennt one - so that the net cost will not be that great. You will not only come out cheaper but you will be spending time on the bike instead of online and on the bike stand switching out components.