If you can't see your destination on the screen, type it into the blank box under the Navigation tab, then hit Enter - the map view will whizz along to your destination. To have the game calculate your waypoints, click on the star in the map, then select 'Plot Route'.
If your range is so low (it may well be in starting ships) that there is no possible combination of hops to get you to your destination then the route plotter will fail. The easiest way to fix it is to get a better FSD, downgrade/upgrade modules to D grade (lightest) or remove modules if possible.
Re: Plotting a Course to Sagittarius A Basically you just need to orientate the galaxy map and move to a point 1000 or less ly in the direction of the core and plot to that point, rinse and repeat.
Inner Scutum-Centaurus ArmColonia is an Independent system in the Colonia Region within the Inner Scutum-Centaurus Arm. It is approximately 22,000 light years away from the Core Systems, and for a time was the most remote inhabited star system from Sol.
Elite Dangerous is a space simulator game by Frontier Developments based in the year 3307. You control your own spaceship in which you can participate in exploring a 1:1 scale Milky Way, trade between star systems, participate in bounty-hunting wanted ships, and even pirate other ships for their cargo. 297k.
TL;DR: Route plotting failures are mainly a result of trying to plot a route that's simply too long (over 1000 LY). Try reducing the distance of youe routes when plotting them in the galaxy map.
You can't easily explore nebulae in one direction because of the permit locks. There are still thousands of nebulae out there. Anyway, if you're not in the middle of a tunnel through one of the permit-locked sectors, and if your plotting is set to fastest rather than economic, then perhaps there is something wonky with your map filter. See if you get a better route when plotting with realistic mode. Just keep an eye on your fuel if you do it that way.
Loads of stuff can lock a plot route. Check if "apply to route" is active, turn that off or include more items in the filter. There was also this slightly annoying bug that would always make my first jump a FSD injection boast. Great, except that I always had to plot my first 70+/- jump, then plot the buckyball portion. This can also happen If you're near permit locked sectors (col 70), and too low on fuel.