I would say the number one thing to get right in the initial sift is your spelling and grammar. Mine was woeful when I first started applying and I didn’t see it as too much an issue.
It took a good 2-3 years to start progressing to further stages. My applications hadn’t really changed much, a bit of spit and polish here and there. However, my spelling and grammar was spot on. I honestly think this helped a great deal.
I was a lorry driver before I started and I think our applications would be very similar, so you are in a great position. You just need to polish that app and make it stand out from the rest. Cover safety, concentration, customer focus, time keeping in your answers, there’s more obviously and a quick search on this forum will help you. No need to buy books online, everything you need is on this forum. I know it is as it’s how I eventually got the job.
Good luck.
Edit, I will say now, I don’t take anywhere near as much care with my spelling and grammar now - just in case I get picked up for anything, as I usually do!!