The sooner you put money into a pension, the more it is worth. So get some in there soon.
But you need to plan separate pots for different things. Some savings, some investments.
First - emergency fund. Cash savings that will cover at least 3-6 months expenses. Keep this as cash in a high-interest savings account with fairly easy access (not a fixed term one, but one that only allows a few withdrawals a year or has an interest rate penaly for withdrawing without notice will discouraged you from spending it without thinking). A cash ISA is also an option for this.
You also need a similar cash saving fund for any planned spending in the next 5 or so years - house renovations, maternity cover etc.
Then investments - this covers 'non cash' vehicles (most commonly stock market) that should grow faster than cash and keep ahead of inflation. Investments are for money you won't need to touch for a minimum of 5 to 10 years.
It's useful to have your investments in a mix of an ISA (can access at any age, no tax on growth or when you withdraw) and pension (can't access until your late 50s, no tax on growth, pay some tax on withdrawal but almost always less than the tax bonus you get when you pay in).
The most efficient pension is an employer's pension that pays in before both tax and NI (a private pension gets a tax rebate but not the NI saving). Make sure you pay in enough to get the maximum matched payment from your employer.