What skill are you willing to dive into regarding the theme - (style realistic, cartoony, modern, architecture,) if your more wanting to strive for realistic builds it’s not really plugins that can make buildings realistic it basically comes down to using textures, meshes use of lighting and more.
If your willing to learn to build short answer is you: practice and learn is a part of improving, or learn how to accomplish these a type of style your wanting but there’s a bunch of tips and suggestions you can learn, to dive into building is just practice.
Find images of the things your willing to create or make always start simple don’t just dive right into huge projects or realistic builds take pictures of things you want to recreate into your creation you could even right down different options in a notebook and save those for later progress and then putting them into your creation.