Will a memory upgrade help ?

The really answer is in what you do with the system. If you can track that you fill up your physical memory and the system is resorting to paging a lot, you would benefit from more memory. If not, it's wasted money. Same thing for the SSD. That's a very fast SSD, so aside from replacing it with an expensive NVME drive, you likely wouldn't notice any difference.

If you are a gamer, you could look into a video card upgrade, depending on what you have and what games you play. If not, you are most likely best suited to bank the money for something else.

WEI looks like this:

I build custom computers - mainly gaming computers as a hobby/side business. Even if you get the fastest memory you can find and it was double the speed of what you're replacing, you won't get any noticeable performance increase on anything except some benchmarks. It's not noticeable. I gave up tweaking memory years ago - there's no point! It usually makes the system unstable if you overclock it too.

If you want to make a dramatic performance improvement on your computer, buy an SSD Drive and install Windows on it - use a second drive for storage if you can. If you can't run two hard drives (like on a laptop), then get an SSHD hard drive - you can get a 1 TB mechanical drive with an integrated 8 or 16 GB SSD drive on the controller. It makes a huge improvement that's very noticeable!

If you play games, upgrade your video card - another huge improvement.

Most everything else is a waste of money - even processor upgrades don't provide as much improvement as a new HD or video card.