I have to agree that a .22lr revolver would be a good firearm to learn on.
One problem that some have with the revolver is that they like to put the non-dominant hand thumb behind the hammer, then when they transition to semi-auto, the thumb automatically goes behind the slide.
Grip the revolver the same as a semi-auto (with both thumbs along side), cock it with the non-dominant hand thumb for single action. you should not have any problem.
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)