Back to the original question.
You need to bodies and lenses.
You have a 5D3 and a 70-200. The cheapest way in kit wise would be one of the new 7DIIs and a 300/2.8 IS.
7D2 = £1599 and you can get it on 12 months interest free
http://www.wexphotographic.com/buy-...atch=b&plid=&gclid=ci3cipac2micfqgcwwod-lkara
Then there is 300/2.8 IS for sale in the used forums for £2300
Editing software. I seem to remember Gary Coyle using Photoshop Elements - Gary can you caption in that? Cost £60. Alternatively Lightroom is £105 and I know Tobers does his captioning in that. I think you may need an add-on for that though.
Or use Elements for editing and Photomechanic (£100) for captioning.
4G dongle £60 (or £30 on FleaBay). £5/month for a data SIM.
Insurance £300/year.
Then you need wet weather covers for your gear - you can buy cheap ones.
I am assuming that you have a monopod, case for your gear, card reader and the other peripherals.
You should be able to get your own card - if I remember that you have the right number of paid for images. If not there will be smaller agencies that will take you on.
If there is coverage in League 1 and 2 in Scotland then after a while you could start there with the agencies. To start with I would shoot non-league to make sure that you get used to shooting editing and to check that your images are up to scratch.