Hello and welcome to the forum.
Firstly, I would stay away from pick guns and bump keys. If you want to learn how to pick, it´s a pick set and that´s it.
I can´t see any label on your upper picture but it could be quite similar to the other one. Yale doesn´t necessarily have security pins but the keyway is usually more demanding than some others.
Where are you from? If you are from the wrong side of the sea

, then you could get a Shclage or Kwickset to start with.
But to your question, it really depends on what padlock are you looking at. Like house locks, there are easy and difficult ones. Search here to get some suggestions about suitable locks for beginners.
Don´t pick locks which are in use, if you have those padlocks laying around you can start with them. What padlocks do you have?