I'm not a financial expert, but I understand this stuff pretty well. If you want to PM me I can give you a basic run down.
Basically it works like this though.
If you have a 401k or 403b (it's basically the same) at work you can contribute up to $19,000 ($19,500 in 2020) to it per year. This money is put in there before taxes, so no taxes get taken out. You can't touch it until you retire. When you do take it out at retirement, it will be taxed, but at the income you're making then (which is likely less).
A lot of employers match up to a certain amount. So if they match an amount, you should at least put that in. Not only are you not getting taxed, but you're getting instant doubling of your money from an employer.
A Roth IRA is an account you can put money in after taxes. You can put $6,000 a year into it. You put this money in after tax. But! When you retire, you don't have to pay taxes on it. So as it accrues, all of the money that it makes won't be taxed when you take it out.
So the basic idea is this:
401k - give at least what your employer matches because that's instant doubling of your money.
After that (if you can)
Roth IRA - $6,000
After that (if you can)
401k - Maximum ($19,000 of our own money in 2019)
After that (if you can)
Your own stock investments
The only disclaimer is if you make more than $194,000 (or $203,000 in 2020) as a household you can't use a Roth legally.
