What information to put in livre journal regarding recettes?

I successfully registered as auto-entrepreneur on 19/8 and have been working steadily for a couple of clients since then. I issue an invoice to each at the end of the month. I am aware that I need to record various information in a day book (Livre Journal) - receipts and purchases. In respect of receipts can you advise me of the dates and information I need to use.

My clients are in the UK and pay me in GBP into a UK bank account. On the last day of the month I prepare and email them an invoice for the work I have done that month. The invoice shows two amounts - one in GBP, the other in euro. I check the exchange rate for the euro on that day on the Banque de France website.

One client pays me the same day, i.e. last day of the month, the other pays me the first week of the next following month, i.e. invoice 30 August, paid first week October, so its about five weeks. The exchange rate has sometimes changed by then. Also, I don’t always move the money immediately to our French bank account, as we have my husbands pension money paid into the UK account too I often wait until I have a reasonable amount to transfer to get a good rate with the money exchange company.

My questions are:

1. What amounts and dates should I use on the Chronologique de recettes?
2. Should I print out a copy of the UK bank statement each time to prove when I was paid the money (no paper statements as it is internet bank)?