It is hard if you want to start your hosting business without money, unless you have a big site with huge traffic then you can start a simple hosting site where offering hosting plans there. The simplest way is drive traffic from that site to your hosting site and convert it into customers, so you will have a stable revenue without spending more on advertising or maintaining it.
You can start your business with small invest. If you want to sell webhosting, start with a good VPS (10$ a month). And if you want to sell VPS, there is some cheap dedicated server like soyoustart. I have sold VPS few years ago with only an OVH dedicated server which cost 60$ a month.
for selling VPS OVH does have the cheapest good quality dedicated servers however their support is the worst.
if you are looking just to sell VPS and can keep up with the 60$ a month cost for 6 month at least then go for it. (be sure you have the skills to set things up or you and your customers will face a lot of issues)
if you want a much cheaper alternative you can always use a reseller plan. Resellers have very strong servers behind them and extra features. you can also resell VPS using reseller plans.
I wrote a complete article about this. read here: https://forumweb.hosting/13169-reseller-vs-vps-dedicated-(explained).html
Well that's the pain every startup has. Banks do not entertain in such conditions as well. In my personal opinion, if you have money, you can start any business, if not, even good idea's will not help.
I would highly discourage starting a web hosting business with little capital. You would be doing a disservice to your customers because you simply won't be able to sustain a stable business. What you could do, if you have the skills, is pick up some freelance work, build up your funds, then look into web hosting down the road. Good luck!
You can learn to use third party resources. Gain small different profit by becoming reseller. When you accumulate few customer, then only upgrade yourself to rent machine and manage it by your own. Follow upgrade your self again with purchase own server and host at data center.
In my opinion first you purchase a Reseller plan from any hosting company and start reselling it. When you feel that you have enough money with you then start thinking to buy a VPS then to dedicated server.
If someone have a master idea about web hosting business and really want to do some big things in hosting field, Then He should prepare a business model or business presentation for the investors and start searching investors in web hosting forums, there are plenty of forums for the web hosting business and you can open thread on the forums so people can contact you and you can present your business model to them for a good amount of investment. You need to careful while dealing with your idea presentation in front of people because there are lots of idea thief in the market. So in every step, you need attention while dealing with people/parites. If you found someone who is ready to invest /to participate in your business model. Then I suggest you go with legal documents for the proposal to go further with the person you are dealing with. Having safe side is always a better option in terms of business.