Welcome!
For searching over models and datasets (and Spaces), you could use either the available Hugging Face Hub Endpoints or the Hub client library (see list_models and list_datasets).
Then you can specifically download the README.md
file for the dataset or model, which would be the dataset/model card: (Downloading files)
I would suggest using the Hugging Face Hub client library so you can do something like:
import huggingface_hub as hf
models = hf.list_models()
datasets = hf.list_datasets()
# Downloads the file and returns the local path
card = hf.hf_hub_download(models[0].modelId, 'README.md')