contracting and consulting. house painting for instance, computer programming, landscaping, etc.

Drop-shipping has inventory but you don't hold it.

Services.

Professional services of any kind typically don't require much, if any inventory - because you are selling your time and expertise.

My personal experience in founding/running a business and mentoring other founders is that you will need both an interest in (bordering on passion for) whatever you sell - and decent business acumen. Without an interest in what you are selling, the temptation to offload the work will be high - and you will lose control of quality and serving your customers (hello, Boeing). Without business acumen, you will struggle to keep the business viable (mostly - there are a few exceptions out there). Also, get a good accountant to do your monthly books and taxes - they are worth their weight in gold.

If you are in the US, SCORE is a non profit of volunteers who either are current or former business owners. They offer mentorship to people wanting to start a business and are fantastic.

Finally, be aware that business ownership is high risk high reward, and a shit ton of work. If you are successful, you can be really successful. You can also lose your house.

Feel free to DM me if you have specific questions about getting started.

There are plenty of commission-based businesses where you wouldn’t need to hold stock, but would order materials upon request. You could even have the client front the cost of materials and have them pay the rest upon completion.

Website with ad revenue?

What skills do you have? What skills are you willing to learn?

Being a middleman. Someone I know ran a business selling T-shirts with print on them and never touched a shirt. Just took the order, and then ordered it from some shop in China to directly ship it to "his" customer.

Basically just ran a website, took money, and worked customer service if needed.

Right now a startup using AI can get some funding if you have a half decent idea and a prototype. It's dumb, but that's a thing.

B2b saas type offerings can make some bank. Wrap an aws service and resell with your own flair..

You can sell data, but that requires an idea.

Otherwise buy some glass beads and get your ass on etsy