I went to the mall because I want to buy some clothes and sunglasses.
A: I went to the mall --->Shopping mall ni ikimashita. ショッピングモールに行きました。
B: I want to buy some clothes and sunglasses.
-->Fuku to sangurasu wo kaitakatta. ふくとサングラスを買いたかった。
B node A
Fuku to sangurasu wo kaitakatta node Shopping mall ni ikimashita.
B kara A
Fuku to sangurasu wo kaitakatta kara Shopping mall ni ikimashita.
A nazenara B
Shopping mall ni ikimashita nazenara Fuku to sangurasu wo kaitakatta (node/kara).
(This is not common way to say, it is a bit formal way, however, if you are English speaker, it is easier to remember because the sentence order is the same. )
Good Luck with your Japanese Study :-)