where can I get access to AlexNet?
The ImageNet data is online: http://www.image-net.org/.

The data descriptions says:


  14,197,122 images, 21841 synsets indexed


However, you don't need to train a model on all of the data from scratch, since you can use pre-trained models, e.g. in TF/Keras. See the docs: https://keras.io/applications/.

I don't think the original Alexnet is available, but a lot of other models are ready to load from Keras. You may also find a Alexnet version stored as .hdf5 or so online (which you could load with Keras/TF).

I don't know what you actually want to do, but here is a simple example of how to use a pretrained model (VGG16 in this case) in Keras.