Ha! hello Dennis,
yes thats perfectly normal for the first time and as you say you will get recoil off a gun that is to short and often a kick in the face once or twice. Stick to the gun with the longer stock until you want to buy your own and use 24g cartridges as well they will make a lot of difference. Try to ware some padding on the shoulder if possible, a thick jumper or something like that will help. If you can, have a go with a semi auto, they have less recoil.

As a coach I use only 24g Hull intercomps when teaching because they have the lowest recoil on the market and I never get a complaint about recoil, so give them a go if you can.