is there a way to make nouns adjectives?

na przyklad, if u wanted to say 'castle town', can u just say 'castle' as an adjective? or would it have to be said 'town of the castle'? (how do u even say it anyways?)

castle (noun) = zamek (noun)

castles(noun) = zamki (noun)

zamkowy/or zamkowe (adjective)

In some languages a noun can be used as an adjective but probably because of Latin usage this can not be done in Polish. You would have to say 'town of the castle'. When even in english would you say 'castle town'? It sounds rather strange. Maybe something like zamek za miastem or zamek przy zamku sounds better. Zamkowy would be used in an address more for instance 22b ulica zamkowa.

Hmm, I have been doing a lot of this lately. Here are some examples:
(polish adj - masculine endings here, substitute a or e in place of y for feminine/neuter adjs respectively)
N - celność - accuracy
Adj - celny - accurate

N - rosądek - sense
Adj - rosądny - sensible

N - pilność - dilligence
Adj - pilny - dilligent

N - wojsko - military
Adj - wojskowy - military

N - osoba - person
Adj - osobisty - personal

N - szczęście - happiness
Adj - szczęśliwy - happy

N - pewność - certainty
Adj - pewny - certain

N - tradycja - tradition
Adj - tradycyjny - traditional

N - bezpieczeństwo - safety
Adj - bezpieczny - safe

You'll notice a general pattern emerging...

Between the noun and a conecting adjective there is bound to be similarities. In English a house and the word housed but the question is one of grammar. In English I can say iron and then the word ring and even put them together as iron ring but in Polish it will be necessary to say the ring of iron or find an adjective if one exists. Castle town, as the question asked would indeed have to be transliterated as town of the castle (although the example is a little bit strange).