Newbie Need Help – VAT and Account Fee

I am totally new to Amazon, I did some searches, finally I registered Amazon UK. here are some questions, hope everyone can help !

Amazon charged me £25 for account fee, my understanding is if less than 40 items sold per-month, Amazon will charge on per-item fee basis, is £25 only for deposit or will charge every month despite how many items you sold ?

Do I need a VAT number before my FIRST listing submit ? my understanding is if my turn over under £75000 and do not use FBA, I DO NOT need a VAT number, am I wrong ?

I found can apply VAT number through Amazon seller central, is this work or I need to register on UK HMRC web site ?

Appreciated if everyone can help me