Welcome to the forum Dominic, probably a bit late now but i'll share my experience. My first event was the UK champs last year and my robot did absolutely awful, despite that i learned so much from that one event that i was able to build a fairly competitive robot this year. Whether your robot is up to the task of fighting or not i would suggest trying to get to an event and put it in some fights, it'll probably lose but it gives you the chance to see how it performs and any problems will show up immediately.

With regards to radio gear, i went for a very cheap Blade tx and whilst it does work it's far from ideal and this year in particular it failed and my robot went into a full speed spin whilst me and another roboteer were leaning over it. Alex (Eventorizon) was kind enough to lend me his Dx6i and i have to say they are well worth the money, very easy to use and just an all round fantastic bit of kit. I used that with an Orange r615 from Hobbyking which is a great, cheap rx, didn't mis a beat all event.

I hope your build goes well, you've definitely come to the right place though, everybody here will offer advice in bucket loads and there is a wealth of useful info to be found reading through build diaries.