Hello all, newbie here looking for some urgent help.

I have recently (Saturday) bought myself a Black 2003 Mercedes Vito 112 CDi.
The last few mornings it has struggled to start but has got there eventually.
This morning it wouldnt start for love nor money and the battery ended up going flat on me
It seems to be turning over fine but it just does not want to fire up.

It has been fine any other time during the day and starts 1st time, but the 1st time everyday is a struggle.

When I collected the van from the previous owner, I was told that when I start the van I need to wait for the clock to go out rather then just the yellow coil light, but only when its cold starting.
However on my old Ford Transit Connect I only had to wait for the yellow coil light to go out before starting.

Would this make my problem Glow Plug related?

Also, as I had drained my battery flat this morning I wanted to try to jump start it off of the other halfs car. How the heck do I go about gaining access to the battery?

Thanks in advance for your help.