How do we verify someone is an accredited investor before we talk to the? Is it illegal to talk to them about joining the fund if they are not accredited? (thinking for people with high salaries specific that we think may qualify but aren't sure of)

As a manager, you need to get to know every potential limited partner before you pitch them, including doing research to understand if they are accredited. At the ned of the day, you need to use your best judgement. This is governed by general solicitation regulations, which are explained below:

https://govclab.com/2022/06/28/general-solicitation/