I'm new to Reddit, so I want to pre-emptively apologize if I should be posting this question on a different forum. I'm also no expert in PC building, so I appreciate any patience.

This is the build of the PC in question:

Make & Model: Dell XPS 8700

Processor: i7-4790 CPU @ 3.60GHz x64

Installed RAM: 24.0 GB

Motherboard: 0KWVT8 Version A03

BIOS: Dell A13, 6/13/2018, UEFI

Current Graphics Card: NVIDIA GeForce GT 720

My son got an XPS 8700 pc from his grandpa, and he has been mainly using this pc for indie games with low-graphic demands. However, lately he's been playing some games with higher graphic-demands on lower settings (Deep Rock Galactic), and he also wants to play Helldivers 2 which he installed but it wouldn't let him play.

Steam says Helldivers 2 requires an Intel Core i7-4790K processor at minimum, but this PC is i7-4790 (no K). This leads to my questions:

1. I know I need to update the graphics card. It looks like from my research that the GTX 1660 may be the best for this build without too much bottleneck, but I'd like to see if you have recommendations since my research on this may be flawed

2. After upgrading the graphics card, would we be able to run Helldivers 2 on i7-4790, or would there be a need for more upgrades beyond the graphics card?

Any answers or comments are very much appreciated. Thanks