Do you have a budget for plants?
I’d love to be doing a new boarder - you’re very lucky!
Before you do anything it might be worth having a bit of a think about the kind of garden style you might like. It is often good to look at your house and take a lead from the type of house you have. Loads of styles out there that could give you ideas - cottage, modern, formal, woodland, jungle/exotic, Japanese, wild, eco etc. Also what colours do you like - do you want all colours or a limited palette? A restricted colour palette is more calming, lots of colours are more exciting.
I’d be looking for evergreen climbers, trees and shrubs for the back layer. Then adding long flowering tall perennials like Japanese Anemone, Gaura, Verbena bonariensis for the middle layer, and then at the front something that will give good ground coverage like Hardy Geraniums, ladies mantle.
Personally I like flowers that bloom for a long time. Some people like to have flowers that blooming different shorter times which I have done to an extent (tulips) but I’ve mostly gone for plants that will look absolutely brilliant from about July right through to November.
Also try and repeat the same flowers/shrubs/trees instead of one of everything, as repetition adds a sense of calm.
The Middle sized Garden on YouTube is brilliant for advice on all things garden design and planting boarders. I found the book New Small Garden really useful too.
Have fun!