You will often be offered tea or coffee or a little something when you visit
someone. Of course the polite thing is to accept, whether or not you
actually plan to drink or eat. The main thing, grammatically speaking, is
that what is being offered comes at the end of the phrase, as you can see
below with the word "tae" (tea). When you are expressing simple likes and
dislikes, you place what is liked or disliked in the same place as "tae,"
whether it's people, places, or things.

An maith leat (pronounced "unn my latt") means "is it good with you" and is
the appropriate way to ask if you like something. So "An maith leat tae?"
means "Do you like tea?"

An maith leat tae? ("unn my latt tay?") = Is tea good with you? (do you
like tea)
Is maith liom. ("iss my lum") = It's good with me. (I do.)
Ní maith liom. ("nee my lum") = It's not good with me. (I don't.)

Ar mhaith leat (pronounced "air wy latt") means "WOULD it be good with you"
and is the appropriate way to ask if you WOULD like something.

Ar mhaith leat tae? ("air wy latt tay?") = Would tea be good with you?
(would you like some tea?)
Ba mhaith! ("ba wy!") = It would! (yes, please!)
Níor mhaith! ("neer wy!") = It wouldn't! (no, thank you!)

Lastly, note that in each time, you use either "leat" (with you) or "liom"
(with me). "Le" is a prepositional pronoun (like ag or ar) that gets
conjugated. Here are the conjugations for le:

le (with)
liom (with me) linn (with us)
leat (with you) libh (with y'all)
leis (with him/it) leo (with them)
léi (with her)

So if you want to say something like "John is with Mary," you'd say "Tá Seán
le Máire." But if you said "He is with her," it'd be "Tá sé léi." "She is
with us" is "Tá sí linn."