As far as your questions about studying theology v. studying the Bible: terms like Arminian are like abbreviations. They denote a whole universe of thinking--in this case about issues such as predestination, election the meaning of the death of Jesus on the cross, to what extent a person can freely chose to follow Jesus and whether or not it is possible for a person to lose salvation.
When one of us uses that term, we are writing paragraphs with one word. It's an 17th century version of abbreviating to do a text message.
Should you study theology or the Bible? Of course, you should study the Bible.
One small benefit in being familiar with basic theological terms is that to do so facilitates your engagement with the Body of Christ in discussing matters of truth. You can say more things in fewer words when you are able to use the terms with knowledge. (Of course, you can only use those terms with other people who are familiar with those terms.)
A second small benefit of being familiar with theological terms is that they connect you to believers in other times and places. We are a part of a movement that extends over more than two millenia and all of the continents on the earth. There is some some value in understanding that people in other times and places have thought the same thoughts you think and have reached conclusions that may edify you in your own struggle for truth.
What we are discussing here is something that few of us would bring up in a Sunday School class. But, I believe that there is value in these discussions, among those who know the technical terms, because when we are using terms such as Arminian and Calvinist we are struggling with the most profound issues of our salvation and how we come into relationship with our Lord and remain His followers-and even how we take the Truth to the people who do follow it.
Good stuff (imho).