I've created a Jupyter notebook that presents a simple probabilistic model linking diseases (cold, flu, COVID-19) to symptoms (fever, cough):
Assuming that this model is accurate (which is probably not!), it allows you to answer questions like:
What is the probability of having COVID-19 in the occurrence of fever but without cough?
This model is programmed in Python, using Lea, a package dedicated to probabilistic programming (PP).
Note that the goal is to let you discover PP and Bayesian reasoning, not to provide you usable/trustable figures (even if the calculations are plainly correct).
Take care of you!