The Bible was people writing to others for their and our benefit. Each writing meant something specific to its original audience. We must look through the author's eyes for that original meaning. We look at whose speaking, where they were, their audience, their goals, and the even the words they used. We look at the writing through their eyes to understand its original meaning. Once we know that, we can know what lessons they were teaching. Then, we can apply those lessons to our lives today. This is the historical-grammatical method of Bible interpretation.
Let's look at how the Bible was written to see why this makes sense.
The Bible was written by over a dozen authors over a period of thousands of years. Each author has a different style, audience, and goals. They use three languages with the Greek also having Hebrew elements in it. There are multiple genres whose writing techniques range from historical prose to figurative imagery. Some introduce new theology while others might build on older theology without specifically referencing it. They're also not all in chronological order. We must weigh in these truths to get the true meaning of a single passage of Scripture.
There's also a redemptive story, how Jesus Christ saves us from our sins, that runs across the whole Bible. What each author writes is part of that bigger picture. God progressively revealed more of His plan of redemption over time. An example is that the Mosaic Law speaks of a sacrifice for sins, the prophets promise a Messiah will suffer for us, and the Gospels reveal Jesus Christ dying on the cross. People who read the later books will get even more meaning out of the older ones. So, we must always ask how a specific passage ties into the overall story of redemption.
You just ask these questions as you read a passage.
Genre
The Bible has different types of writing. Examples are historical prose, songs, parables, and apocalyptic writing. They require different methods of interpretation. So, what is the genre? What interpretation rules will we be using?
Grammatical
Interpretation starts with the sentence itself. Ask, "What do the words and grammar mean? Do any phrases have a pre-existing meaning in that culture? The author's own signature words or phrases?"
Historical (human history)
Ask, "Who is saying it it, to whom, and for what reason? What problems did the audience have that the speaker was trying to solve?"
Historical (divine history)
The Bible isn't just a bunch of books: it has both recurring themes and a redemptive story running through all of it. God's Word tells us who God is, how He reveals Himself throughout history, how He saves us through Jesus Christ, and how He expects us to live. For spiritual meaning, we ask, "How does this passage tie into the overall Bible? And the redemptive story of Christ?"
Theological (SWORD Method)
"What does it say about God? About man? And how does it teach us to live?"
By combining all of this, we are able to look at what the author wrote through their eyes. We will understand it in its original context. We will learn the lessons it teaches. Then, we apply them to our lives today.
Bible studies done this way will often break a passage line by line, word by word, to focus on what God's Word says instead of what the preacher thinks. Your church should be doing this themselves or teaching you to at home. If not, find one that does so you know you're learning and obeying the actual Word of God, not just people's opinions.
Here's some articles and courses to help you learn more:
7 Principles of Biblical Interpretation by Lifeway
6 Principles of Biblical Interpretation by Bible.org
Courses from BiblicalTraining.org (others):
How to Read Your Bible (course for everyone)
A Guide to Bible Study Methods (for small-group leaders)
Biblical Hermeneutics (seminary-level, deep dive)
Note on courses: Interpretation (or Hermeneutics) courses teach how to read the Bible. Old and New Testament Overview courses will summarize the individual books. Systematic Theology summarizes doctrines with relevant verses. Doing this combination will give you more out of all future readings. That's why both "foundations" programs and seminaries often require one of each.