temps looks fine to me, just like for school use, browsing internet or using docs, temp is around 40 to 45C
When I game, it is around 70 C so I don't think fan is bad
On the Newegg, I found this corsair builder 600w 80plus bronze atx psu. it is 57 dollars and it has 20 dollars mail in rebate. Is this a good quality psu to buy for single gpu gaming pc?
Yes HDMI into the graphics card. And Newegg has a great video on installing Windows and final touches. The process might differ a little because the video is 5 years old but it should be fine.
That CPU is lacking, if you intend to stream get at least an i5. Otherwise you'll be ok with that PSU but I'd advise, if you plan on upgrading anytime soon, getting a better one.