Welcome and congrats!
I would suggest a good fresh water regulator, I have the adjustable water regulator from Valterra. Also a water filter.
After several bad experiences with sewer hoses, I would highly recommend starting out with a quality sewer hose!!! Don't pinch pennies here, stay away from the cheap hoses, that you use metal clamps to tighten! I've tried those with little success.
2 yrs ago I invested in the Rhino Flex sewer kit, with the 10 foot extension. Whole set up was around $40-50 bucks at Walmart. It was money well spent, no leaks, no hassle!! That with a slinky to flow down hill to drain and I've had no issues! Also invest in a good pair of rubber gloves or a box of disposable latex gloves at Home Depot. Great for handling sewer connections..