Hijet Not starting. PLEASE HELP!!!

Hi, I have a hijet. It's a 51 plate with 70,000 miles.
Owned it for just over a month now without any problems whatsoever.

But yesterday I ran out of fuel, and had to walk to the petrol station and come back with 5l of petrol to get it going again. It then ran fine for the rest of the day and I came home and parked it up. This morning I started it up but it was making a funny grinding noise (mainly when I was in 3rd and 4th), but I took it straight to the petrol station, put another £25 in and brought it home because the noise continued. Parked it up for about 3 hours and now I've come outside, tried to start it up... and nothing.
Not turning over. No lights coming on. Nothing.
I don't know a lot about engines but I'm hoping someone can help???

Thanks in advance,
Kurt

There are two little wires/connectors on the live terminal of the battery....

Go and have a play with them.