What does someone who doesn't know shit about investing and retirement and stuff need to know about 401ks?

If you can, put in at least as much as your company will match. The match is bonus pay for future you.

Invest all the money in an index fund that tracks the S&P 500 and has the lowest expense ratio possible. Vanguard VFIAX is one example among many. Over many years that should give you an average return; not amazingly good, but also not terrible.

If you are earlier in your career, contributing more money now can be very beneficial when you are in your 60's. Though don't put in too much that you become short on cash. For example, I was overly aggressive with 401k contributions early in my career and missed the chance to buy an affordable house in 2008 because I did not have enough cash remaining for a down payment.

If you don't know much about investments, there should be a target date fund that is a mix of stocks and bonds. Pick the date that is closest to your expected retirement date (eg if you're 25 and aiming for retirement at 65 you'll pick the 2065 fund), and invest in that one.

A good thing to ask about is the expense ratio. This is how much the fund will cost you in fees, and can seriously impact your returns. If the fees are 1% or higher then seriously reconsider that fund.

John Oliver did a piece on 401ks a while back that was very informative.

Make sure you're adding (at least) the max they'll match. I get paid hourly and they match up to 4%. I make them do the math so that no matter how many hours I work, it's 4%. The office lady tried to make it easy and just calculate 4% on a 40hr week, but I work over 40s a fair bit. Nope, thanks, but I want all 4%. Will it mean early retirement? No. Does it matter in the least? No, I work hard for my money and I want it all. There's never a reason to turn down free money from work.

The minimum you should target for contributing is the max company match - so in your case that sounds like 3%. In general, you should make sure you’re putting enough aside into an emergency savings fund (usually 3-6 months of normal expenses) and after that prioritize retirement savings.

In your company’s 401k, you’re going to be limited in terms of investment vehicles. The default is usually some kind of targeted date fund. Those spread your invested dollars across multiple industries and international funds. The benefit to the targeted date funds is that they rebalance your portfolio so that your money moves to more stable (but lower return) investments as you get closer to retirement. Some programs are very limited in their options, but I think that they all have targeted date funds.

Another possibility is using an index fund that tracks something like the S&P. These funds also are diversified (although not so much as the limited date ones). The reason a lot of people like them is that there are several alternatives that have a very low fee schedule versus managed funds - if you pay high fees, you’re cutting into your growth. The Vanguard funds are among the most popular for that reason. However, that may not be available through your 401k.

Basically your 401k should be a set it and forget it kind of thing. Pick a percentage, pick a fund, and don’t think about it until next year. You should review it annually, and you do have the option of increasing your percentage contribution if, for example, you get a 10% raise and want to start contributing 4% instead of 3%.

The person you’re meeting with possibly will not be allowed to give you investment advice. They can review your options and answer your questions, but if it’s just an HR person and not a financial advisor, don’t expect financial advice. You’re going to want to go in there having read these threads.

The big thing is not to overthink it at this point. I’m going to hazard a guess that you’re relatively far away from retirement, so getting in now is absolutely the right thing to do, but it also leaves plenty of time for you to educate yourself more. The part about meeting the 3% match at a minimum is just because that’s basically free money. If you are making $30k, your 3% would mean putting $1k per year into the 401k. Your company would match that, which means you’re making money right from the start.

There are multiple websites that allow you to calculate your retirement savings based on your age and how much you invest per year. It’s good to become familiar with the way the math works. Your 401k may provide such a service, but there’s plenty of free ones as well.

Good luck!

I don't know how 401ks work but buying individual stocks is basically like gambling. You don't need a financial advisor but you should treat financial planning like a part time job reading and learning until you are confident in your decisions.

Also, everyone brags about their wins and forgets to mention their losses.