Bought a house with these flowerbeds. I have absolutely zero gardening knowledge. How do I begin to figure out what to do?

West facing garden
Current first step is to replace the wood which has rotted around the border but otherwise I’m not sure what to do

I’ve tried image searching every plant but I must suck at taking pictures as I was barely able to identify any of them so have no idea how to care for them or trim them back etc.

I’d also like to eventually have the flowerbeds covered in quite a few different varieties of colourful flowers/mixed with ground cover as I personally don’t like the dirt showing (also a pain with weeds). My problem here is that I have no plant knowledge so I’m not sure how to begin to find what I want, if it will grow and if it would even look good.

Any advice would be welcome