u/Moneygrowsontrees

I have a few house plants I'd like to trade/exchange or even gift, but don't know how to connect with interested parties. Is there anything in the area? Preferably north-ish since I live in Hamilton, but I'm not unwilling to drive.

I am not a huge DIY person, and this isn't full DIY as I'm hiring people to install the shed and run electricity, but hopefully the knowledgeable folks here can help me prevent major mistakes.

I am in the planning stages to have a 12' x 16' shed installed in my back yard. I live in southwest Ohio, so summers can be hot & humid and winters can be frigid. The purpose of the shed is to give extra space to my adult son who will be coming to live with me. There will be electricity but no running water/plumbing. He will sleep out there and spend much of his time out there.

I will be using a mini split for heating/cooling, drywall interior walls/ceiling, and LVP flooring (these things are all DIY). I will install a ceiling fan to help with circulation. I am meeting with both the shed installer and electrician this week.

What I know about the shed (so far):
Premium-grade lumber and materials (marketing speak)
30-year architectural shingles
Treated 2×6 floor joists
3/4-inch plywood flooring
LP SmartSide panels with 30-year warranty
Solid block footings
4" roof overhang
gable vents

My most pressing questions:

1. How should I do the base/foundation? I am looking to balance cost & durability/comfort. I am open to anything including a concrete slab, but I will have to hire the work out.
2. I was going to do a loft for storage (not for extra living space) but now I'm thinking it might make more sense to have a flat ceiling at wall height (8') so I can insulate above the ceiling and allow the two gable vents to move air. Am I thinking correctly here?
3. What are critical questions to ask the shed installer?
4. What are some easy-to-make mistakes that I should be aware of before I get started?

I am happy to answer any questions and discuss options. Thank you all so much in advance for helping me sort this.