As above - do have a plan about how to get to the the event and how to get back again. Put all your stuff in a bag and you'll get a tag for your bag to identify it at the end. I've certainly never heard of anyone having stuff nicked from their bag, but obviously it's sensible to avoid having all your credit cards and expensive stuff in the bag.
If it's a bit chilly on the day, wear an old sweatshirt or something that you don't mind ditching at the start - many of the big events will collect these up and donate them to charity afterwards. The same goes for a bottle of water if needed. As the others say, I'd carry as little as possible - for me it's gels (plus one spare if case you drop one), a blister plaster and a hair grip, with sunglasses on head if needed.
Even though you are on your own, you'll need to provide an emergency contact number on the back of your race number so just make sure that person is happy to be contacted if something happens - even if they aren't at the event itself.
And finally - get to the start early so that the logistical stuff can be organised in plently of time so that you have time to "relax" before the race starts and really enjoy it. There will be lots of marshalls to help you
I used to work in Swindon Old Town and head out for some lunchtime runs. Mill Lane which is a short cut from the motorway to Old town has a good hill. And as Mill Lane turns into Westlecott Rd, I used to do hill sprints up a footpath off Mill Lane.
The old railway line is a nice route and the overflow carpark for Nationwide has a track going round it (not a proper running track, more a walking track) so good for intervals. There is also apparently a trim trail there too, but don't quote me on that.
Being a little more generous, on the kits where I can see the flag, I do sort of get what Stella was trying to do. Although I still hate it. But on the cycling kit for example, the flag just looks like a couple of rubbish stripes.
So I don't pretend to be the most sartorially knowledgable person and am very under-qualified to comment in this space, but...c'mon....it's not good.
I'm genuinely v v excited about the Olympics and will be glued to the telly. And I get lumps in my throat and teary eyed when I see athletes performing to their best and achieving their dreams. But standing on the podium in an insipid blue strip which is missing the red bit of of our red, white and blue flag is all wrong.
The pic on the BBC sport website says it all - our greatest sports stars are all looking decidedly glum and faintly embarrassed to be wearing it.