Does anyone here know anything about jewellery?

Well overdue but im finally looking at proposing to my long term partner. I went around the jewlers in a local town today and frankly became overwhelmed with the different metals, carat and clarity of the diamonds etc. In fact I felt stupid for knowing so little.

£3k is my budget, most I can afford and it seems fair enough.

Been searching for hours online trying to get myself a bit more clued up. I came across this, is anyone able to advise whether this is worth the money?

https://www.goldsmiths.co.uk/Goldsmiths-Platinum-0.95-Carat-Goldsmiths-Brightest-Diamond-Ring-GS+EE1+975095-N/p/06018767

It's the style I'm looking for. Just want to make sure I'm getting the most for my money, tbh. Not sure if going for a highstreet brand like this is the way to go.. what's the quality like etc.

Thank you, anyone who might be able to help!