First off, Hi. Nice to meet you.
Have you considered finding a priest locally to talk to? It can take a bit look around to find a good spiritual director but he can help in many ways.
Personally,
I Try to think of prayer as conversation between me and God.
While there is formal prayer, there is also the rest of your day you are just talking to Him in your head having a more or less one way conversation.
Sometimes you can get a response…like an answered prayer or religious experience but otherwise it is stuff like hey God thank you for my cat and a mental tirade thanking Him for everything I can think of about my cat. Or oh man I am having a bad day today followed by me venting to God.
For the bible I personally I am fond of psalms and at least one of the four Gospels (Mathew, Mark, Luke, or John). They each tell a the same story about Christ but the intended audience (ie Jews Greeks, gentiles or the church) was different for each book so they differ slightly.
For entertainment choices these reflect you own personal choices and internal changes more than anything.
I do watch some horror still but my perspective has changed on it.
My personal music taste changed naturally over time, I started with Rob Zombie in my teens I ended up Gregorian Chant Before bed.
It was not so much an overnight thing as more I slowly have a growing desire to put more Godly things in my life. Like I find myself going to adoration more because I want to. I like the smell of incense at home to remind me of Church. I like religious music now to mesh with my constant babble to God.
The liberal views issue is more of a personal transition as you learn more about your faith.
I personally had several Wiccan friends. They were always accepting of my Christianity in High School. I remember siting at a fast food place with them all dressed in Gothic at the time and me in my Praise Jesus shirts.
As far as your boyfriend that is a complex one. I have met several Satanists in life and it really depends on their philosophy. One belonged to the hardcore cult version which does sacrifices and he left before he got too deep. It was very dangerous and not compatible at all with any part of being Christian.
However while in a hospital I met a laveyan satanist and I was able to have many good theological talks with him. While we differed in faith it was not anything compared to the cult version. For him it was a “be a good person” but “hedonism is fine” focus and “angels are misunderstood”. The danger is still present, but it is more that people do not understand what they are messing with. Demons are fallen angels, satan is the highest fallen rank…a fallen cherubim. Very smart and very devious. Christ described him as a “murderer and a lier”.
Again good spiritual direction is helpful.
God Bless on your journey