During importing of assets and textures, I was attempting to recreate the multi-sub material of the buildings, I didn't realise I had to make a separate material for each map used in the building. But once that was done I found that UDK had only 5 slots available, yet I had 7 materials to fit in. I got some advice to split up the asset if possible, which it was. So I reimported the buildings as two separate assets and then it worked out fine.
There was a very strange problem where I couldn’t use the play from here option without it spawning me in the same place each time, no matter where I clicked. It would spawn me between the buildings and I would fall through the level. I also found out that a lot of the times when I dragged in an asset, it would also appear in this same spot. I still don’t know what caused this, but adding a player start solved the problem with falling through the level.
I read somewhere about not using a skylight since light mass makes it obsolete, but I couldn’t find a light that had an alternative effect. I needed an overall light that covered all of the level evenly, since it was a cloudy day, the light was dispersed and not sharp either. So I used a skylight anyway and that really helped.
I also found out about fractured meshes and dynamic objects, I made the billboards destructible and also all the boxes in the level moveable.
Also added a fog actor and then learned how to animate a camera through matinee.
Also recorded some sounds, the background noise was done by recording using an app on my phone, holding it outside my window, where you can clearly hear the traffic from the motorway. There were some birds too but I thought that this didn’t matter too much, it helped to add variation. Someone actually beeped their horn at one point, which was great for the effect I wanted. The whistling wind sound I made myself and let the background noise distort it a bit so you couldn’t tell as much! The machine sound was my old external hard drive which lately has become extremely loud when switched on!