Just opted out of my pension - bad idea?

I just opted out of my pension at work on the advice of a colleague because I'm finding it hard to save and wanted to get rid of extra outgoings that I feel are not necessary at the moment.

I'm 23 and this is my first full time permanent job straight out of uni. Earning £15,400 a year which is shit and works out around £1,100 or so a month. The pension on my wage slip last month was over £60 and I found out I could opt out so I did. I think my employer matched it but I'm fuzzy on the details as it wasn't very well explained.

Should I opt back in? I also was paying a pension in my last job but I'm not sure what became of it because I was made redundant after the shop closed down.

I currently only have £400 to my name until the next payday in a few weeks, I can manage until then but I'm sick of not being able to save. I rarely buy anything for myself except food and transport costs as I don't have a car. I want to start saving for driving lessons but also start building up the balance in my account as I'd ideally like to have at least a grand in my account at all times in case of emergencies.

I have no idea where to begin, I feel like cutting out the pension for the moment was a good idea but I'm now having second thoughts. [pension] [savings]