For tinkering around, just use Googe Colab[1]. They offer free hosted Jupyter notebooks and have both Nvidia GPU[2] and Google TPU[3] runtime options available.
Here[4] is a notebook that shows how to install CUDA into an environment using the GPU accelerated runtime.
Only major downside is that resources aren't guaranteed (see first section under "Resource Limits" here[5]), so you sporadically may not be able to start a GPU-accelerated runtime session. But that shouldn't be much of a blocker for tinkering purposes.