It's pretty early to get into too many specifics, but some general ideas to think about ...

Cities tend to grow out from a center ... some reason the first settlers built the first tavern or mill or whatever started the settlement at this spot. So a city founded where two important roads cross (or where an important road crosses a river) will tend to grow in a general circle around the crossing point. A city that grew from a natural harbor, will tend to expand in a semicircle from the first dock.

Whatever the origin of the city, security will be an issue. Some cities grow up in the shadow of a castle that offers general protection for the region. Some cities are afforded a sort of natural protection (try marching an army on Venice). Some cities build strong walls to keep everyone out. The title includes the word "Renaissance", but I am not sure how literally you are using that word and whether you are referring to the historic period or simple the general concept of a 'rebirth'. If you are thinking of the historic period, then there are lots of really interesting new styles of 'star fortifications' and urban planning that you might want to draw inspiration from.

In any event, cities, by definition, mean lots of people that require lots of water from somewhere. If this city is along a large freshwater river (like the Nile or Mississippi) then you have that covered. If the harbor is non-potable water, then the city will have been founded near a stream or river to supply fresh water ... or there should be some sort of aqueduct to bring in fresh water from somewhere else. Whatever you decide, it creates opportunities for your map to have some interesting features.

Good luck.