Go to Safety Regulation at the CAA website.
CAA there is a guidance document there which should tell you all you need to know
ELGD
From memory you need to be 21 before you can hold a Licence, to hold that licence you need 5 years experience, 3 if you do the modules through a 147 approved training school, such as Bristol, AST plus others. The ELGD document should tell you.
So
Apply for the 13 modules with NO maintenance experience and apply for your license afterwards.
Not true.
and
Apply for the 13 modules WITH maintenance experience and get your license straight after.
Yes but you will need 3 or 5 years experience before you can.
There is also a time limit from passing the first module (may of change recently) used to be 2 years but it may of been extended.