I’m very curious as to how well you will pick up switching. I never thought of anyone having to do that later in life. I wish you a lot of luck. About the only advice I can think of has been mentioned. Use a 22lr simply because it’s going to be cheaper and will go much further when practicing the basics. Semi autos are good but use all you can like bolts, pumps and levers. If you have an area to walk or hike with a rifle and shoot, that will help if you can do it regularly. Kind of like the military and their seemingly pointless drills. Those drills are meant to imprint the rifle to the shooter, but you will need to focus on the left side. During the walk, mount and shoot the rifle at random things like small rocks, bushes, and crotches of trees. Maybe it’s not too important that you shoot each time, but the repetition will slowly improve your ability and confidence. Don’t forget to include kneeling and seating as part of the hike.
