What is the exact order number? This MCU exists in DIP, QFP and 32 or 28 QFN (MLF) package. See section 3 (page 11) of the datasheet
The package drawings are found in section 37 (starting from page 436)
Have a look at these FAQ articles for further help:
- How does KiCad know which symbol pin represents which pad of the footprint? (Make sure you understand this as your symbol will only be compatible with the pin numbering of one package)
- Tutorial: How to check footprint correctness? (Workaround for missing features in KiCad V5 and earlier) (Gives an example of how to check if a footprint could fit your part)
- Tutorial: How to make a footprint in KiCad 5.1.x? (If you can not find a fitting footprint)