There are two methods of interstellar travel.
There will be some form of "Faster than Light" (FTL) travel. This method will be based around an engine that requires fuel. However, "FTL travel" is misleading. From our earthly perspective, its extremely fast, but it takes 4 1/2 years for light to travel to our closest star.
In Dual Universe, FTL travel will be the slower method of traveling between stars. It will require time and resources (fuel). It will be primarily used when traveling to unexplored star systems.
The faster method of travel between star systems is the use of Stargates. Stargates will allow near instantaneous travel between developed star systems.
"Going from one solar system to another for the first time will take time and fuel (we don't know yet what will be the time range yet from one system to another). Building Stargates won't be mandatory to go to another solar system, but it will be way faster, nearly instantaneous, to keep real incentives for stargates. This will also make two kinds of space travel gameplay: it will be quick to go from one colonized solar system to another where stargates exist. it will be much slower to explore uncolonized solar systems, where everything remains to be done" 
Flying from a planet to another should be a real achievement in our game vision. So it would not be available on the first day of the official release. If a player is here from day 1, it might be weeks, maybe a few months before the travel from planet to planet becomes possible. This is still a topic heavily discussed in the team. However, later on in the game, when the global tech level of civilizations built by the players will have reached a certain point, it will be possible for a new comer to simply buy or be given a ship to fly with as soon as he arrives in game (he will still need to learn a few skills to be able to fly it however, but the basic levels should be reachable between a few minutes and a few hours, according to the flying construct complexity). In short, the game experience for a player present from day 1 might be very different from the game experience of a player coming several months after the game has launched, also different from the game experience of a player entering the game one year after official launch (where many solar systems will be, without a doubt, already discovered and colonized).