I need help upgrading

[gearshiftstudios]

(I posted this on another forum but I thought this one would be better for my question. btw how do i delete a post cuz I wanna delete this from the other fourm)
Hi, I'm new to building and upgrading computers. My dad the other day gave me a Dell Optiplex 390 DT (link for the specs below). I want to upgrade the GPU, CPU, and the RAM (links to the them also below) for gaming. I know I can upgrade the RAM to 8gb, but I'm worried about the stress the GPU and CPU will put on the system with the crappy PSU that comes with it. I've read that the PSU cannot be changed for the model I have and if I was to put the parts in, the system would overheat. Will I be able to use the parts effectively without frying my computer? Also, would changing the case allow for a better PSU?
Specs: https://www.cnet.com/products/dell-optiplex-390/specs/
GPU: https://www.newegg.com/Product/Product.aspx?Item=9SIABRD6488844 or https://www.newegg.com/Product/Product.aspx?Item=9SIA85V4R42232
CPU: https://www.newegg.com/Product/Product.aspx?Item=9SIA1K66646914&ignorebbr=1&nm_mc=KNC-GoogleMKP-PC&cm_mmc=KNC-GoogleMKP-PC-_-pla-_-Intel+Processors-_-9SIA1K66646914&gclid=Cj0KCQiAgNrQBRC0ARIsAE-m-1yhJ7tePSJ_t7wLEHNr7uRyzkA4qDQd_z-Lk8qGbOoJoWotpD_klUIaAoo-EALw_wcB&gclsrc=aw.ds
RAM: https://www.newegg.com/Product/Product.aspx?Item=N82E16820233599&ignorebbr=1&nm_mc=KNC-GoogleAdwords-PC&cm_mmc=KNC-GoogleAdwords-PC-_-pla-_-Memory+%28Desktop+Memory%29-_-N82E16820233599&gclid=Cj0KCQiAgNrQBRC0ARIsAE-m-1x8tmMSYwTyJekeVGZ3fsE4wjuTrLosf8l25HmCVh1uJ6zWnz_9xykaAr5WEALw_wcB&gclsrc=aw.ds

Thank you!
PS: If these parts won't work, what would?

 

[sid.sinha12300]

if you are going to upgrade then each and every thing is good but maybe the graphic card might not fit in your case

 

[gearshiftstudios]

if you are going to upgrade then each and every thing is good but maybe the graphic card might not fit in your case

Okay thanks! So the PSU is good? It's 265W and there's no upgrade options from what I've researched.

 

[sid.sinha12300]

if you are going to upgrade then each and every thing is good but maybe the graphic card might not fit in your case

Okay thanks! So the PSU is good? It's 265W and there's no upgrade options from what I've researched.

dude your cabinate is too small to do changes 🙁 it is better to build a new one

 

[william p]

To not upgrade the PSU , and to run in the DT case you will want the GTX1050Ti low profile video card.