I would recommend starting with grammar, that's how I learned Japanese and it's the most effective method for adults. There are a set of 250 or so common words you need to learn to start having basic conversations. The rest is up to you to practice speaking English as much as possible. The way I'm studying French currently is to think of basic things I would want to say, like asking "Why is the sky blue?" and finding a translation of it. Then come up with as many variations as I can think of using different language constructs. It also helps to get a grammar book or teacher to explain the why and how of the grammar constructs you're learning, so you can learn to construct new sentence patterns on your own. For example, I came up with sentences like these for my French studies:
Why is the sky blue? (is X)
Why is the tree not blue? (is not X)
Why do you sleep? (do, intransitive-verb)
Why do you eat apples? (do, transitive-verb)
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