do they have any educational system in the army?

Hi, depending on your age you could join as 'Junior Entry' and attend the Army Foundation COllege at Harrogate. As part of army training you also do a lot of work in the Education centre and will try to complete your Level 1 or 2 in Numeracy, literacy and ICT if you didn't achieve the grades at school.
Whilst serving you will be put on an Apprenticeship programme, usually a level 2 or 3 depending on what trade you join. Throughout your time in the army you will do both trade courses and education courses run at your local Army Education Centre (AEC) which depending on the course you will get civilian recognised accredited qualifications. Also throughout your time in the army education and quals are seen as important so every service personnel is entitled to £175 per year to put towards an education course (could be a fork lift truck course or a medical course or could just be a windsurfing course). I hope this helps!