DenisJpn

its not great, would really suggest stretching for a cx550. then you are set for any possible upgrade path. you can also perhaps get a System Power 9 or Pure power 11 500w from Bequiet. both also cheap in certain regions. 

there shouldnt be any issues. 
 
but you must upgrade the PSU. dont think it has the connectors, and the wattage (which is usually not a concern) is a touch to low to be running with a moderatly powerful GPU. 

i cant see the entire case, but any medium size GPU should be fine. 

that is a 250w PSU at the max.
 
it can only provide 216w towards the CPU and GPU. 
 
spend 50$ towards a cx450 or cx550 and get a used rx 570. 

there is allways a limiting factor. so there is no way you cant have bottlenecking in any type of system. 
 
but using your PCIe bus you can go up to a Titan V/2080TI
 
you should probably upgrade to 8GB of ram at the minimum. 
what 450 watt?
 
how much are you looking to spend?

uff well maybe watch some fps tests for your cpu and then try to pick a gpu thats not too far ahead.
i think a 1050 would maybe work. 1050ti maybe but unlikely i think