Ok, so the only way is exchanging money? How adding money to the network was done before there was enough bitcoins?

Bitcoin is money.

You have a few options.

You can provide a product or service and receive bitcoins as payment.
You can exchange your local currency for bitcoins.
You can beg and hope people will donate bitcoins to you out of the kindness of their heart.

(I suppose you could also consider scamming/stealing them)