Depends on how long you see yourself in the military and what you want in the future.
For example:
1. In the future you want to work as a driver for Eddie Stobart then join for a few years, you'll have some experiences, be able to spin BS in the pub with credibility and have some good times.
2. You want to join for a few years then go climb the corporate ladder in banking and finance to earn real money join as an officer.
3. There are certain specialist functions and jobs/trades where only soldier (Private to Warrant Officer) are trained and employed AND officers have to defer to their specialist knowledge. Make sure you know what jobs are what.
4. Or, you see the army as a career and are thinking about joining for a few years as a soldier then getting a commission. Nope! So much can go wrong in just 2 minutes that will destroy your career even as a little private, and you would never have the chance of being accepted as an officer in the future. If you fancy being an officer just go and apply for that.
5. If you have not been to uni and you are capable, get your arrse off there and do that, do you hear me? Meanwhile go and join the local reservist infantry unit/paras as a soldier and find out what it is all about for 3 years whilst you are at uni. Then go and apply as an officer, it will make you a much better officer.
6. Finally, the same nag as above about uni, but this time go and join the Officer Cadet Training Unit and you will walk into a commission at the end of uni.
With my magnificent superpower of hindsight I would do option 5.
Hope that helps a bit.