The first problem to tackle is "what is an odor"? An odor is a chemical aerosol or gas, which are small molecules suspended in the atmosphere. To track the odors of pizza or burning wood you would first need to identify the molecules associated with the scent. One example is α-pinene, which is the molecule that gives pine trees their scent. Food cooking typically gives off other volatile organic compounds (VOCs) and the particular matter associated with it. VOCs physically and chemically combine to form more types of aerosols and there can also be increases in ozone.
Meteorology, emissions sources, and atmospheric photochemistry are combined in chemical transport models (CTMs) so that the air quality can be predicted. One example is WRF-Chem, which is used for large regions and many sources. Another example is CALPUFF, which is better suited for near-source impacts and capturing the effects of complex terrain. The reason you want a model with chemistry is that molecules can be reactive and will change as they interact with other molecules turning them into things that no longer smell like pizza or wood burning. The reason you need a meteorological model is so that pollutants will be advected with the wind and interact with the moisture budget, solar radiation, terrain, etc.
For large-scale plumes you can simulate your molecules as being emitted at a constant rate from a point source and see how this plume evolves with time. For smaller scale flows like a pizzeria, you may need use a model that can accommodate small scale features like buildings that will have an effect on atmospheric flows. Lastly, you'll also need to account for other emission sources as the perceived strength of the smell is also going to depend on what else you are smelling (e.g. car exhaust) and these other aerosols may be reactive or combined with the odors you are interested in tracking.
Once you have done this you will have a time varying plume of "smell" as output from your model. This will likely be output as a number concentration of aerosol molecules per unit volume per grid box. To turn this into "odor strength" is probably a harder problem and one I am not familiar with. As a first order approximation though, wherever the plume is located, so is the smell; and the higher the concentration of molecules, the stronger the odor.