Some other things to consider:
Founding that second city is going to start eating away at your treasury, which in the mid-term is going to slow your rate of research.
Working tiles that produce commerce at the start is a benefit for researching those early worker techs. Fish come to mind, these are great first builds, if you can build a workboat in your starting city, I can't think of when you wouldn't want to do that first.
Obviously, building the settler first is the fastest way to get it out. Building a worker or two to chop the settler is recommended because you'll be able to make your cities more useful. But the goal is to expand, and technology is a part of that, so you can't neglect the benefit of working commerce tiles from the start (if you can, such as fish or riverside tiles).
Founding that second city is going to start eating away at your treasury, which in the mid-term is going to slow your rate of research.
Working tiles that produce commerce at the start is a benefit for researching those early worker techs. Fish come to mind, these are great first builds, if you can build a workboat in your starting city, I can't think of when you wouldn't want to do that first.
Obviously, building the settler first is the fastest way to get it out. Building a worker or two to chop the settler is recommended because you'll be able to make your cities more useful. But the goal is to expand, and technology is a part of that, so you can't neglect the benefit of working commerce tiles from the start (if you can, such as fish or riverside tiles).
