I've been running my firm since 2005 now and the first year or two is extremely hard. Don't expect to get rich quick is the first thing I would tell anyone who is starting up on their own. You also have to be realistic have clear goals to aim for.
As for getting into debt, this is something almost every business has to do at some point or other. When I first started up, I had to take a loan out on the strength of purchase orders quite a few times. This isn't something that will have a negative impact on your business and is common practice.
The most important thng in any business startup is to identify your intended market and create something unique to offer, whether it be in the level of service or products offered. That way, you have something over your competitors. In my business, I chose to offer a much greater level of service than my competitors, while this has bitten me on the bum a few times and caused a few sleepless nights, it has also generated a great deal of repeat custom and positive free marketing (word of mouth).
You need to be able to multi task when you run a business and be able to communicate at all levels, whether it be to a MD or a rep. You need to be able to put your points across and listen too. I struggled with this in my first year, as I didn't feel confident talking to, and selling my business to, MD's etc. I learned quick