Small garden low budget DIY advice?

Hi everyone! Just moved into a maisonette with a garden, very excited! The garden is very small and needs some work. I had a landscaper over who quoted £7.5K to do a small patio, lawn, and flower bed. He emphasised that it was more expensive because there is no direct access to the garden – It’s a first floor maisonette, to access the garden you have to go up the front stairs, through the kitchen, and then down steep stairs at the back to the garden.

So I thought perhaps I’d give it a go myself. I have a budget of about £2K, but can probably save up more and add more over time. The main thing I want is a patio area, as I really don’t like the gravel. I’d also like flower beds with wood borders, and feel like this shouldn’t be too difficult? What would you suggest?

As the garden is so narrow, only the ground directly along the right side gets any sun.