Not really.
You are thinking of the USA, which has the very simple 18000ft system, no Class A below that, IFR flight plan file-able for any airway route which is at/above the airway MEA (or direct), Class D which can be penetrated with a 2-way radio contact (just need your callsign read back by ATC), etc.
In the UK, there is a lot of Class A (no VFR), and a lot of Class D (no entry without a clearance).
Everything else is Class G which is free for all, and that's how you use it.
Just get the map, draw a route in Class G, and fly it
