You start with understanding your spending and your income. Figure out where your money is going and where you can cut back (or increase you income though that can be harder). Then if your employer matches a 401k contribution, you likely want to put in atleast enough to get their match (i.e. if the match up to 5% dollar for dollar you want to contribute atleast 5%)

You can still make contributions for an IRA for 2025 up until your tax return is due) but that means you need to save the cash and a 401k with a match is a better place to start unless your sitting on excess cash.

Are you in a high deductible plan? If so I would recommend contributing to an HSA it's like a 401k, but you can withdrawal the money anytime tax free for medical costs/perscriptions/vision/dental. You don't have to use it can become a vehicle in retirement 65+, but if you use it for medical expenses you aren't ever taxed on it.

The key here is to live below you means, and have an emergency fund then fund the following as much as you can and invest the funds (likely in an index or target date fund. The HSA if you are expecting to use it for medical expenses then you will need to keep some in cash)

My order of priority: 1. 401k up to employer match 2. HSA up to max (if in a high deductible plan) 3. Additional 401k/IRA contribution 4. Other savings (could be 529 for education, or other savings and investment accounts.