Starting out goose hunting

I’ve never hunted geese or ducks before and would like to give it a try. The farmer not far from me is fine with me using his fields for Canadas sometime. My only shotgun is a 20g break action single shot with modified choke, I have a box of 3” #2 hevi-steel shot (hard enough to even find that in my area), everything else I have is lead shot and obviously I won’t be using it in this case. I’ve used this single shot for shooting alot of grouse, turkeys and some hares. I’m not an amazing shot but not bad. I have some time to pattern this gun with the #2 steel shot I have before I want to try for a goose or two.

I know my single shot is far from optimum for waterfowl but it’s what I have and I’m perfectly fine with waiting half a day for an excellent shot if that’s what it takes, just looking to get my feet wet so to speak. If I got a bird or two after sitting for 5 hours I’d be happy.

I’ve read some old threads and did some other reading online, got a general idea of things to start thinking about but what tips can people give me in this case? Figure with the 20g and steel shot I’m probably going to be maxing out at 30y at the very most

I'd go BB for geese. 2 works but can be marginal for a perfect kill in my view. I use 2 for mallards.

Hevi-steel that has bismuth??? If so never mind what I said...

If you're going after geese I'd recommend looking for a 12 ga. pump or semi. Should be plenty of good used guns that won't break the bank. In general, shottys are less costly than large caliber rifles.