If you're young, stay the course
I think Warren Buffet said that for the novice, just buying index funds will pay better in the long run than other funds becuase of the low management fees on them. Short of that, you'll obviously want a blend of small cap, mid cap, large cap and international funds.
I would say to also look into a RothIRA. You can only put in $5500/year, and it's post-tax dollars, but the good thing is that you aren't taxed on it when you take it out in retirement. So, it can grow free from capital gains taxes until you take distributions.
Just for round numbers, if you wanted $100k in retirement but took $25k of that from a Roth IRA distribution, you would only get taxed on $75k. Where if you take it all from 401k you get taxed on the full $100k.
I am absolutely not a finance major or financial planner, btw.