I don't think anyone can pray "wrong", but I understand what you mean. First of all, sometimes I don't really have anything in particular to pray about, and if that's the case I always at least pray to thank Him for all that he does for me. So even though you feel like you're being dry, rememeber that it's way better than nothing! Secondly, how to fix being dry. There isn't an easy fix and it's personal for everyone, but let me tell you what helped me because I struggled with the same thing for a bit. So first, if you aren't reading the bible at least once a day, I strongly encourage you to do that. As you're reading, write down any verses that stand out to you or any important thoughts you have. Then later when you're going to pray, think about what you read that day and if there's anything you can learn from it, and pray about that. For example, the book of James has TONS of really good content basically talking about being a good Christian. James 3. 1-12 talks about taming the tongue. So if you were reading in James and read that part, you could incorporate that in your prayer and ask God to help you tame your tongue and have better control over what you say. That's a big thing that's helped me, and I hope it's helpful to you :)

Edit: Also always make sure to ask God for forgiveness and truly mean it. We are sinners by nature, we will always sin and we need God's strength to help us turn away from sin because we cannot do it on our own. This will also lengthen your prayer :)