If you skip the first leg on a ticket you will be classified as a no-show and all sub-subsequent flights are cancelled.
So the answer is: no you cannot skip the first leg.
If you are willing to pay then contact the airline and change your ticket or just use the money you are willing to pay for a hotel at the airport.
What happens if I miss the first flight of a round trip?
If your flights are part of a complete round trip purchased on a single itinerary/airline, then the answer is no, since the first flight/airline will automatically cancel your itinerary after you miss the first flight. In some cases they may be able to even confirm you on the next flight.
Can you miss a leg of flight?
Canceling the reservation is standard procedure if you miss the first leg of an itinerary. Not necessarily so for a subsequent legs, but absolutely for the first leg. Actually if you miss ANY leg on most airlines all remaining flights are cancelled.
Do you get charged for missing a flight?
Depending on the airline, travelers may be charged a rebooking fee to get on another flight. Some airlines may also charge the difference in airfare — meaning a missed flight can be a costly inconvenience. Southwest, on the other hand, never charges change fees — but travelers may have to shoulder the fare difference.
What happens if you no show for a flight?
In general, being an airline no-show for a ticketed airline flight means a traveler will lose any value on the ticket. If a passenger books a roundtrip ticket, and decides to change the return, most U.S. legacy airlines now charge $200 plus the fare difference.