What are some ideas for online business which involve the least investment?

Many ways to start a business don't require much time, money, or risk, and let you focus on getting started.
There are ways to bypass many startup costs, including inventory, warehouse, and retail space.
Start a dropshipping business, a digital product or online course, a charitable business, a membership program, a pet business, or a fashion boutique.
Dropshipping is a low overhead fulfillment model that's hands-off and scalable.
If you want to sell products online, you don't need to handle any products yourself - you just need to make the sales and pass orders on to your supplier.
Local and overseas suppliers are available to work with. You can test the market and test your product before investing in your own original products.
A t-shirt business that focuses on customizing products is called print on demand and involves the use of freelance design sites like Fiverr, Upwork, Dribbble, and 99Designs.
Print-on-demand services are more expensive per item, but the product doesn't actually cost you yet.
There are many print-on-demand platforms you can use to create custom products and get your designs in print.
If you've got the knowledge and creativity, you can create an original book to serve a particular demand in the market.
To get started with self-publishing, you can use print-on-demand platforms like Lulu xPress and Blurb.
While you can order a single book, you can buy in bulk and guarantee a certain number of sales if you pre-sell or crowdfunding your book idea.
The best businesses to start are online businesses with digital products. These can include original instrumental beats, stock photos and information products.
If you can turn your talent into a digital product, think about using Shopify to offer those products.

I was thinking of doing Internet sales as a reseller.

Any business requires investment and start-up capital. I agree that you need less investment by acting as an intermediary between the buyer and the warehouse site. But at the very least, you have to spend on creating a good website and advertising. In addition, there are many opportunities to open a business abroad. It has some advantages, as available governmental and local grants and subsidies. Don't restrict and cut back on the company due to lack of finances; it's better to think about where to find the necessary capital. If you believe that you'll get rich right away once you start a business, you're wrong. You'll have to take out loans more than once, but any entrepreneur passes this stage.

I can say with confidence that thanks to revenue operations, it is much easier to monitor the process of moving leads to purchase and perform predetermined actions when changing the stage of the sales funnel. This has several advantages: the business can more accurately monitor each manager's work, analyze why leads drop out of the funnel and improve business processes.

We all are looking right now towards ideas to help us develop a business from nothing. The tendency is understandable as you can close the company whenever you feel like it, and you'll have no money lost. I am sure that with the market we have nowadays, it is impossible to find something that would attract customers, so I would suggest you start working on simple jobs but on a higher post, such as the one described in https://ndandp.co.uk/director-disqualification/ and I am sure that it would be better for a big group of people.