Depends on you what you plan to do.

You need to do the boring stuff, plan and research your products/services, identify trends which you can be one of the first to surf, or find new ways to offer the same for less in existing markets. Not everything is about cost, (think rich people buying bespoke or low production run highly innovative products or services), but mass market is about doing the most with less, economies of scale & efficiency. Some of it is also about building a relationship with the customer, you might be the best rock star hacker around but if you have no ability to be nice to customers with all that being nice entails, who will put up with you for long, so presentation and reputation can also be key if its not essential like choosing your electricity provider.
If you plan on getting into mass market, look at your competitors, find out if the market share is dominated by a few key players with huge profits and see if you can undercut them by taking less profit, even when some global companies can offshore profits putting the country & country restricted business rivals at a disadvantage. If you come up with something innovative, novelty can also draw in new customers (think kids crazes like these fidget spinners currently, or yoyo's in the past) so look at ways to lock them in, either contractually or with reward schemes if you can even lock in a trend or craze! Look at ways you can get customers to market you where possible (brand awareness, bragging rights, trends & crazes), but some companies wont want to give away what they see as a competitive advantage which can make breaking into a market harder, things like trademarks, patents, manufacturing processes, but some patents can also be misdirection to hide what the real trick is.

Some business adventures do not need a lot of money to get going with, think window cleaning business, but others do, like building an electric car or developing a new drug for some specific illness like a specific Cancer.

You will also find, no company will ever admit liability which is what courts are for, but being able to recognise when a business is wrong and putting it right in the most cost effective manner to damage limit is also key. This is where some companies can and do fail, its usually ignorance of sorts which causes this, so recognising your strengths and weaknesses is also useful. What you dont know but need, can you bring in from outside the company at the right price?

So hopefully you can see that there is a lot of work involved in starting up a business, and whilst you might be lucky and wing it on an "event driven" basis, tackling problems when they arise, you still need to be sure you dont get caught up firefighting all the time. If you do, bring someone in to do the problem solving for you whilst you concentrate on bringing the money in. At the end of the day its about getting the balance right, your time & effort for the money you get back. Get that wrong and your startup will fail quickly, get it right when considering all the other variables that exist which the above has just scraped the surface of, and you could go on to be quite successful, but its all about the balance between money & quality of life. Some people value security for their family over riches, which can be useful for choosing employees, so identifying who you may also choose to work with as an employee or contractor can also help.

And finally, just remember everyone has an opinion, and they might not be right all of the time. Dont get your confirmation bias from family and friends, get it from those who hand the money over to you, but find the best way to put yourself in front of those people because it is just a numbers game.