How should one decide which Halacha to follow?

There are so many different halachot and custom nowadays, I have a lot of questions on how should one decide what halacha to follow.

Let's say I have an halacha question. The way I see it, I have three options:

1. Ask my rabbi



2. Look up by myself in some book of halacha, like shulchan aruch


3. Find out my family's custom

Questions:

• What alternative above is the ideal one?


• In case 1, if I find out another halachic source that for me makes more sense than what my rabbi follows, can i do it that way?


• And in case 2, let's say Shulchan Aruch argues with Aruch Hashulchan. Can i simply choose which ruling makes more sense to me, since they are booth authorized halachic sources?


• Can I follow, let's say, Shulchan Aruch, in one matter and, for example, Aruch Hashulchan, in another matter or am I supposed to "adopt" a book to follow in all matters, just as we do with rabbis?


• And in case 3, let's say I don't know whats my family custom in this matter, how deep should I search it to find out?



• If my parents came from a certain city in Poland, should I follow that city custom?

I'm really confused about this stuff!