Quote from: ThisManIsTesting on January 10, 2018, 07:50:55 PM

I signed a transaction with a wallet that doesn't have sufficient balance, this is what I got: min relay fee not met.

That means your transaction did not reach the minimum fee for other nodes to relay your transaction (0 fee because of 0 funds).
It was possible to get zero-fee transaction relayed (and confirmed) in the early times of BTC. But this probably won't ever be the case again.

Quote from: ThisManIsTesting on January 10, 2018, 07:50:55 PM

I'm trying to understand bitcoin why its not possible to create a transaction in the network with an empty balance..

Its not possible because you don't have any UTXO's (unspent transaction outputs). Read more here: https://en.bitcoin.it/wiki/Transaction#Input

Quote from: ThisManIsTesting on January 10, 2018, 07:50:55 PM

.. and what are the network rules, how miners validate transaction then ?

You find the awnser in the first 2 chapter here: https://en.bitcoin.it/wiki/Mining