I've been using AIDungeon (and its successors like NovelAI which are more for advanced users) for years now and have been involved in a lot of the community around it. You are definitely using it wrong, but you are forgiven because AI Dungeon is terribly falsely advertised.
Your main mistake is not writing proper sentences. AI Dungeon is not a Zork simulation where you type truncated commands like "get torch" and receive a response from the computer. It is more like a Choose Your Own Adventure novel generator.
You need to write proper sentences, so instead of "You inventory", try "You double check what items you have in your rucksack." Instead of "You get longsword and bow", you should be typing "You pick up the longsword and the bow." Instead of "You health", you...just don't do that. Maybe try something like "You look down at your body and survey your wounds." If you're really feeling confident, try switching from "Do" mode to "Story" mode, and just start writing a fantasy novel and see what it generates with its next output.
For reference, this is a snippet of an old story of mine I saved:
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As I approached the kobold stealthily, it looked up with its beady, reptilian eyes. It could not see me yet, but I knew it was only a matter of time before it sensed my presence.
I decided to act first. "Let's go!" I shouted to my companions, before rushing towards the small monster with my dagger drawn.
The kobold yelped in surprise before pulling back its bow and firing an arrow at me. I moved to dodge it and barely managed to avoid it. Now in melee range, I raised my dagger into the air before plunging it towards the kobold's torso.
It struck the monster's heart, and blood spurt out of the wound as it struggled, before going still.
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Nearly every sentence there was partially AI-generated in AI Dungeon, retried a few times, edited, and truncated to fit the story. This is how most people in the community actually use this sort of software. It's more like having a buddy suggesting the next sentence in your personal story than a virtual dungeon master. Those who expect it to be the latter generally don't understand it, while those who see it as the former immediately understand what the hype is about and get really passionate about it.
AI dungeon might advertise itself as a game, but in practice it's used as a more general storytelling aide. And it should be noted that it has been rendered obsolete by competitors made by disgruntled fans like NovelAI for a while now (which is a whole other story).