best to upgrade to ssd first, cfm will feel much faster alr, definitely worth the investment.
the 4gb gpu see what suits your needs lor. if u just surf web watch youtube all this, then no need to upgrade, can even consider running off the igpu on ur cpu if have. but if u thinking of starting to game u also need consider what ur demands are, and 4gb of vram is a completely useless metric until we know what card u r looking at.