We’re to start

Apart from the basic costs involved in having a legal marriage ceremony, everything else is up to you.

The best place to start is to sit down and work out a realistic budget. Start with what you can afford/want to spend, put aside the money for getting the legal stuff done, and then work out what your priorities are for the rest. Allocate money for the most important things first so that if you run out, it's the 'nice to haves' that get dropped, not your 'must haves'.

Speak to some people who have got married local to yourselves as costs vary massively depending on area. There was an article on here recently about cost of weddings that might help!