This 3D Model can be printed separately or in parts. So you don't need a multi-color 3D printer.

Dimensions: 18cmx19cmx31cm approximately.

Printing Time: This took approximately two days to print on an Artillery Genius Pro with a 0.4mm nozzle. It will depend on your configurations. For most parts, such as the cloud base and the hot air balloon, I used a 0.32mm layer height.
Recommended Material: PLA

Printing Notes:

I used support for almost all the pieces.
For the hot air balloon, I recommend using custom supports. You don't need any supports on the inside, or in the middle, touching the top of Kirby's balloon head so you can block the supports in that part on your slicer, this will make it easier to post-process the piece and will save you a lot of filament (around 250gr to 300gr). If you have any doubts, let me know.

Printing Settings

Layer height: 0.32mm for the hot air balloon and the cloud base (it will save you lots of time). For the basket, I recommend 0.2mm or 0.24mm. For the columns parts (all of them) 0.12mm/0.18mm. For Kirby (body and feet) 0.12mm.
Supports: Yes. Custom supports are suggested for the hot air balloon. You don't need supports on the inside, or from the printing bed to the top of the head of the hot air balloon, so I recommend blocking that part in your slicer. It will save you a lot of filament (around 250gr to 300gr). On the outside, supports for the hands are also not necessary.
Infill: Around 8% for the cloud base. Else above 8% will work fine.
Wall count: 3 or 4
Print speed: Normal
Nozzle temperature: Use the recommended temperature for your filament material (refer to the material details).
Bed temperature: Use the recommended temperature for your filament material (refer to the material details).