Meeting other Americans or Canadians in Warsaw?

We are pretty sure we will be moving to Warsaw this year. We currently live in Los Angeles, but I'm from Canada as well. We hope to meet other people from either the states or Canada while there. Are there areas that would be good to go to to meet new people? Are there get togethers or anything?
We will be in Warsaw in April for 3 weeks to explore and see which areas we like. Any feedback or advice would be greatly appreciated.
We also have a 3 year old son, and we hope to meet other parents that speak English. I am originally from Poland but my husband is not nor does he  speak Polish, not fluently at least. He does understand some since he's been around me and my family who speak polish, and he will be making it his goal to learn it when we move. But it would be nice to have some people that have gone through this, and are living in Warsaw to chat with.
My husband and I both have our own businesses. I have a clothing line that is sold to stores, and my husband is an artist that does mostly movie posters. So we can work and live anywhere, and since I'm from Poland, and for us converting out US dollars over to Polish zl will be really good. The health care is also one of the reasons we will move, since it's so insanely expensive here. It's just all around way cheaper and better in Warsaw for us.
Hope we can meet some new people when we go over Even if there are any areas we could go to, to meet new people while we are there for the 3 weeks next month, that would be great.