The gtx750ti will fit with your PC, the MB is H110 chipset MB, and it has pcie3.0X16. But like other member said, the PSU is only 180W.
https://support.hp.com/sg-en/document/c04919604 If you want to buy gtx750ti, you have to buy a PSU, like 400W one.
And before you any parts, gtx750ti, PSU, you need to check
1) open the case check youe PSU to see what format it is, if it is the atx format https://en.wikipedia.org/wiki/Power_supply_unit_(computer), and use https://pcpartpicker.com/ to find the good deal. And here is how to choose a PSU
http://www.tomshardware.com/forum/284314-28-power-supply-guides-info
2) Because the gtx750ti is non-OEM GPU, read the linker from nvidia support: When installing an after-market graphics card into a certified Windows 8 PC with UEFI enabled, the system may not boot. https://nvidia.custhelp.com/app/answers/detail/a_id/3156/~/when-installing-an-after-market-graphics-card-into-a-certified-windows-8-pc