help me how to upgrade my cpu

[softmallow21]

Need help and experts advise pls.. I bought from a garage a cpu that has a board socket 775 with intel core 2 duo e6550 2. something ghz.. I wanna ask especially the experts here if what are the best ram and video card that suitable or compatible for my unit that are cheapest but best to buy that can evenly play dota2, gta v, witcher 3, and others on a decent settings.. Pls kindly advise me coz' i dont have any background on upgrading cpu.. Tnx in advance

 

[maxalge]

Need help and experts advise pls.. I bought from a garage a cpu that has a board socket 775 with intel core 2 duo e6550 2. something ghz.. I wanna ask especially the experts here if what are the best ram and video card that suitable or compatible for my unit that are cheapest but best to buy that can evenly play dota2, gta v, witcher 3, and others on a decent settings.. Pls kindly advise me coz' i dont have any background on upgrading cpu.. Tnx in advance

need to know the actual make and model of the motherboard
and the rest of the computer's specs

that said:

dota 2, yes you may get it to run decent

gta5 and witcher 3 not gonna happen without a core 2 quad, 8gb's of ram and at least a gtx 1050