Initial creation of reserves

I am currently reading the book “Where does money come from?” which is co-authored by Richard Werner after I took the “Money and Banking”-class in coursera by Perry Mehrling.

There are certain questions which always pop up in my mind and which I find them either to remain unanswered or I simply don’t understand the procedures.

Assumption:
I assume that Banks do not function as financial intermediaries as in neoclassical economics, which has been proven wrong by Richard Werner in his 2014 empirical study at the latest (but was well known to specialized economists, central bankers and bankers whose daily business are money market operations). Instead, I assume that money is created at the push of a button by a bank deciding to grant a loan to a customer. From this follows, that money in the form of cash/reserves is equally accepted by other agents as deposit accounts, which is why they are exchanged at par (i.e. at face value).

Now, as long as customers make electronic transactions within their bank or to other banks, the reserves of the respective bank remain unchanged. It is only when the customer withdraws cash that the reserves of the bank have to be converted to cash for the case that the bank doesn’t hold enough.

There exists basically two ways of a bank accessing reserves (at least in the Euro-area, the UK and the US):
1) Borrowing reserves in the interbanking market at the Fed Funds Rate (US), the LIBOR rate (UK), the EURIBOR rate (Euro-zone)
2) By selling government securities to the central bank (or doing repos)

So far, I get the part with the interbanking market and why it works. What I don’t understand is the following:

1) If a bank is selling government securities to the central bank in order to get reserves (or making a repo), where does this government security come from?
It is obvious that the security is issued by the government, but the government issues the security against receiving liquidity from the bank that buys the security. However, at the initial stage the bank doesn’t have other liquidity than being able to open a deposit for the government to the amount of bought securities that the government in turn can access. Let’s assume the government would like to access instantly the account of, say, 1 bn Euros and to withdraw the money in cash – will the central bank provide this 1 bn Euros without any discount?

2) As a follow up question: How could money be created if a government does not issue securities?

Thanks in adanvace.
BR