Those slimes are pretty hard to come by.

I spent a significant amount of time trying to locate a slime chunk near my base. It's more difficult than usual to identify a slime chunk since almost nothing ever spawns.

Even though I eventually built a very good slime farm at my base and spend many many hours there, I don't yet have much slime. In fact, I would guess I see maybe 1 slime in ten hours of gameplay in the farm.

I got most of my slime by spending about a week in a swamp. I got 2 stacks of block.