Please stand much farther back so we can see a much bigger area of the space. Can't tell much from what you're showing.

My first question why those tiny plants ? I think 2 big pots filled with bright colored flowers would be all you need .

Aren’t these hydrangeas that will grow quite big and be bushy and beautiful?

No, they are definitely Hibiscus.

Those tiny place will fill in the space by growing to 4 ft. wide each. I need something for in the meantime.

get some large resin pots filled with annuals.

I need something for in the meantime.

Actually, you don't. You do need to move the rock.