Jumping in here because I remember how stressful that first trip can be. I actually ruined a lens element once because I didnt realize how abrasive the mist from geysers can be. Its not just water... there are minerals in that steam that can etch your glass if you arent careful. Since your budget is tight, I would suggest focusing on basic protection first so you dont end up with a huge repair bill later. I would make sure to grab these basics:

• A Tiffen 58mm UV Protection Filter to keep the actual lens glass safe from mineral spray.
• An extra memory card like the SanDisk Extreme PRO 128GB SDXC UHS-I V30 because those files fill up fast.
• A Giottos Rocket Air Blaster Large to blow off dust without touching anything. Be very careful with cheap generic batteries too. I generally avoid the super cheap ones since they might swell in the heat. Better to be safe than sorry with a brand new camera.

Spent some time thinking about the T7 kit. Tbh, you really need to prioritize storage before anything else. A SanDisk Extreme 128GB SDXC UHS-I is a solid, cost-effective choice that ensures you wont hit a storage wall during your trip. For carrying the gear, the Amazon Basics Large DSLR Gadget Bag is a very decent option that provides enough padding for basic travel needs without costing a fortune. If you are worried about power, look at the BM Premium LP-E10 Batteries and Charger kit. It gives you two extra batteries for a fraction of the price of one Canon brand cell. Finally, picking up a pack of MagicFiber Microfiber Cleaning Cloths 6 Pack is a smart, cheap way to manage smudges on the fly. This list keeps you well under that $150 limit while covering the basics.

Unfortunately, the mAh rating isnt as good as expected. I think youll need spares since Ive had issues with them dying, tho Im not sure about the T7 specifically. Youll do great!