To make it look like there's a proper perspective all items should fit together. The fountain bowl, the grating of the fountain well bottom, the floor grating, and the pylons in the background are now like they are cut & pasted all from different images.
The vanishing points for sets of parallel lines are a good practical (but only partial) tool to get it right. The older answer shows a good place for one of the vanishing points, but the floor grating perspective is not enough, every item should be drawn in accordance with it.
No transformation converts an 2D image, which already has one kind of perspective to another perspective. The floor is an exception because it was originally a straight perpendicular view, so it can be converted like the older answer shows. The result, of course, is acceptable only if we can ignore the depth of all grooves and bumps on the floor tiling. But making the rest look right with perspective transformations is a hopeless case. Redrawing everything as seen from the right different directions is the way to get it right. For example most of the pylons should have also something as seen on their sides except in case they are round. But then they should have proper shadings to make them look round.
A relatively easy shortcut is to make a coarse 3D model of the scene for ex. in SketchUP. Then find a good camera and light settings for rendering and use the rendering result as your perspective guide.
Another possibility is to make a coarse cardboard model and take a photo of it. The third way, maybe the hardest one and the one accepted also by purists, is to design the scene as flat engineering drawings and to make the traditional perspective construction from them. The hard part is to learn the method from some descriptive geometry book.
Also artist's perspective methods such as presented in common advanced drawing course books need much work, but they are still easier than construction from engineering drawings.