It sounds like you might need more of a background in grammar if the issue is that you don’t know where to place the vocab. I recommend trying out Lingodeer (paid, but free trial), Duolingo (free, but less useful as you progress), or Kanshudo (free, sentence builder part). Each of these has you practice with the general sentence structure and building it. There’s also BunPro (paid), which is like Wanikani, but for grammar. However, it doesn’t have you practice building sentences, just filling in a specific grammar point.
Once you have a better feel for the order of things (or at least are blanking out less), I recommend giving the Japanese Sentence a Day Challenge a try. As a starting point, I recommend using new vocab or grammar in your posts, but they can really be about anything and often people have conversations. Sometimes you can get feedback on your writing as well about what you can improve. You’ll find people of all levels and experiences in the thread.
For just some general word placement advice, the main verb is last. The time, topic, and subject are typically closer to the front. Any direct objects are usually closer to the verb.