Millennials are pretty smart, but not necessarily when it comes to their personal finances. Although some young people have made smart choices with their money and are well-informed about their finances, others seem reluctant to learn anything about their own financial outlook, perhaps in the hope that what they don't know won't hurt them.

Those are the findings from a recent survey of 500 18-to-29-year-olds, conducted by NextAdvisor, which provides independent research into a variety of internet services.

Here are the Millennial financial goofs that turned up in the survey:

1. Not knowing their credit scores.

Your credit score can dictate whether you're able to buy a house or car, or open a new credit card account. But that's not all. A low credit score can also lead to being turned down for a job and not being able to rent a home. And yet, 39 percent of the young people surveyed said they did not know what their credit scores were. When asked how often they checked their scores, 34 percent had never checked them at all, and another 14 percent had checked them at some point in the past, but not recently.

Getting your credit report once a year from each of three credit reporting agencies is free at, and you should definitely do it. But a credit report does not show your FICO credit scores (you have several but most lenders use scores from one of the three major credit reporting agencies: Equifax, TransUnion, and Experian). To get a look at your score, you can pay a fee to one of the reporting agencies or sign up for a free trial of a credit monitoring service. Or your credit card company or another lender might provide one of your scores free of charge. The three scores are usually relatively similar, so getting one will give you an idea what the others are.

2. Taking on too much debt.

In the survey, 54 percent of Millennials reported they had loans to pay. Of those, 53 percent had student loans--which isn't surprising, given the high cost of education these days. At the same time, studies show that people with college degrees make more on average than people who don't have one, Bill Gates and Mark Zuckerberg notwithstanding. So taking out a student loan, especially if you know you will put it to good use, may not be a bad idea.

Another 13 percent of respondents had mortgages. Although buying a house is a long-term commitment for someone under 30 to make, it can be an excellent investment if you do your homework, can afford the mortgage (plus other expenses, such as maintenance), and get a good deal.

But 25 percent had car loans, which are often a large monthly expense for a new or expensive car when a less expensive used model would do just as well. And 9 percent had personal loans, which might or might not be a good idea.

3. Failure to budget.

When it comes to setting a budget, Millennials haven't quite got the hang of things, with 19 percent saying they don't budget at all and another 26 percent saying they budget for such items as rent and utilities but then spend freely once those items are accounted for. That's better than no budget at all, but it would be smarter to get a handle on all your expenses, make sure you're not overspending, and start the habit of setting up automatic deductions for savings. Doing that while you're young will put you way ahead of the game.

4. Not setting financial goals.

When asked if they had the goal to build up their credit and improve their financial health, 37 percent said no, although 20 percent also said they would like to have such a goal.

For those that did, that's a good start. There are multiple online services to help you monitor your credit and set good financial goals. Improving your credit and financial outlook is important at every age. Knowing you need to do that is an important first step.