When I started working at 24, a friend of mine (a few years older than me) asked me if our company had a 401(K) and what was the match.
I was confused. What's this gobbledygook? So I asked around and got him the answers, and he responded with: max out your 401(K). Just do it. And do not ever think about taking money out of it.
So I followed his advice. At that time, the ~$5500 cut in paycheck (my gross was around $35K, IIRC) stung a little. I was single, footloose and fancyfree, and those extra few hundred dollars a month would have been fun to have. But I stuck to his advice.
Today, almost 30 years later, thanks to that, I have a nice nest egg and don't have to worry about retirement (modulo catastrophic illnesses, of course).
So recently my friends' kids started working, and I gave them the same advice: Max out your 401(K), pick a Vanguard Target Retirement fund, and forget about it. If your place offers a "Mega Back Door" option, use it to the fullest extent possible. And if your company has a HDHCP, put funds in your HSA too.
We have a lot of avenues to save these days. Make full use of them.