Setting up index page with specific categories

Hi,
i am working on this site
https://filthynewyork.com/newsite/

so far so good

i am trying to hack this template and 2 more categories to the homepage
each pulling one post each and leaving the one thats there now the same
just want to add the 2 sections underneath

ive tried different queries/changing the loop and such and i keep getting errors..i do not know where i have made a mistake..

here is a screenshot of what im trying to accomplish
Link to a mock of what im trying to go

im hoping someone can assist and that i made sense..thx so much!