SEC Math

Put in the max and don't look at it or change it until you need it.

Get in, get in now. Put in the traditional 401K whatever it takes to get the match. Then, if one is available, put money into the Roth portion of the company plan. Remember you will pay income tax on the Roth contribution, but will not "get" the money. Neat thing about a Roth is that you can always take out any contributions without any penalty or tax, but if you take "growth" monies out you may be hit with fines, penalties. The terrific thing about a Roth is that you will NOT pay taxes on any growth, it is tax free money. I'm not sure but I think the Required Minimum Distribution rule does not apply to Roth accounts.

We've lost more than a couple of bucks a couple of times, don't panic and get out of the market when it is down, you'll lock in your losses. It will go up and sure as sh^+ it will go down,
Think of your contributions as Paying Yourself First , then pay the bills, then play with whatever money is left however you want. But you've paid yourself and your future first.
Last thing, and this is one piece of advice you should really take . don't take the advice from a bunch of well intentioned people on T-man(unless of course it's trapping related), or anywhere else for that matter, this is serious stuff, literally life changing stuff, can you retire comfortably or early or do you need to plug away at work 'cause you bought shiny new things or a big fancy house instead of taking care of yourself financially:
SEEK OUT A PROFESSIONAL WHOM YOU TRUST
Yes, they will charge a fee for their services, but it is pretty well proven and it has been my experience, that the net gain after fees is much higher with a planner than without.
Good Luck.

I started out putting 15% over 20 years ago with a 3% company match. I don’t miss it and definitely don’t regret doing it. There have been ups and downs over those 20 years but it is crazy the positive affects of compounding over the last 20 years. I started a Roth in addition to my 401k about 6 years ago. I tell lot of people to at least put in to get the company match then if you get a raise split the difference increase your 401k by a percent or two.

And a good rate of return is ?

And a good rate of return is ?