hi, i tried to google it , but i didnt know what should i search 
i'm trying to build a new pc...
i want to choose ryzen 5 3400g with an a320 till later i have money to get a dedicated VGA.
will i be able to use ryzen 5000 later on this?
what about other high end CPU? like R7 3700X or even higher? whats the difference between having best Chipset like X570 and low cost A320 +ryzen 9 3900? if its not more slot for ram and more USB or things like that?
thanks

i'm trying to build a new pc...
i want to choose ryzen 5 3400g with an a320 till later i have money to get a dedicated VGA.
will i be able to use ryzen 5000 later on this?
what about other high end CPU? like R7 3700X or even higher? whats the difference between having best Chipset like X570 and low cost A320 +ryzen 9 3900? if its not more slot for ram and more USB or things like that?
thanks