How to load and split my two individual datasets when integrating datasets in Seurat?
Seurat is expecting individual datasets to be normalized separately prior to data integration. In that respect lists of objects corresponding to different datasets are handy to manipulate each object/dataset individually.

In your case you do not need to do any splitting, you have an object corresponding to each of your datasets.

If you would have started with a single count matrix of all datasets then you would need to split your data based on batches/experimental condition/...