Like was suggested above practice with 38 Special. Load 357 for Home Defense, or Concealed carry. Shoot enough carry ammo to be comfortable shooting it.
I have numerous Revolvers in 38 and 357 Magnum. A safe bet is Over 99% of my shooting is with 38 Special ammunition. My Dillon 550B is normally set up to reload 38 Special ammunition with a 158 Round Nose Bullet, and 4.7 grains of Unique. This is my match and all round use load.
My brother and I both shoot a Defensive Pistol Match one month, and a Steel Challenge Match the next. A safe bet is we average shooting betwen 400 and 500 rounds a month just shooting matches.
My 686-5 has never had a round of 357 Magnum fired in it other than being factory test fired. As this is going to be my new SSR Revolver, it might possibly never have a round of 357 Magnum fired in it until someone inherits it after I die.
My brothers Willy Clapp GP100 is his concealed carry, as well as Match revolver. I do not think it has ever had a round of 357 shot in it other than factory test fired either.
We live in a low threat area close to Mayberry. In the Summer we will both have a couple shotshells up front 75% of the time when concealed carrying for snakes, followed with 4 rounds of 38 Special.
No need to shoot Noisey, Expensive, Hard Recoiling ammunition most of the time at the range shooting paper or cardboard.
By your question you are a new centerfire revolver shooter. I would guarantee you will shoot 38 Special ammunition more accurately than 357 Magnum ammunition off hand.
Get some gunsmith screw drivers. You will need to check the side plate screws now and again, as they can shoot loose. Also pull the grips every few monhs and wipe under them with your oily rag. If you get the gun wet, pull the grips and wipe the frame with an oily rag.
If you wish to take the cylinder off the revolver for cleaning, Take out the Front Side Plate Screw, and the cylinder and crane will slide out to the front. when done cleaning slide the cylinder assembly back in place, close the cylinder, and reinstall the side plate screw.
Enjoy, You have a nice revolver. Keep it well oiled for the next generation to enjoy.
Bob