Hello! Welcome aboard! I believe you should post a thread on the addons and mods section- you will be able to get more help there. To link fuel, you use the FTX-2 External Fuel Duct, and click on to the fuel tank, then onto the fuel tank that is in use from another engine. To get into orbit your rocket/ship must have enough DeltaV to escape the atmosphere and into orbit. The steps are turn 45 degrees when your altitude is 10 000 meters, then keep going slowly and slowly until you see your apoapsis in map view goes over 100 km or how high you want, depending if your ship has enough DV to make it (70 km is the lowest altitude you can make orbit, for your information.) Once you think the apoapsis is suitable for you, then warp slowly and carefully to it. From there, burn prograde until the orbit circle in map view is near or almost circular. Then you're done! You're in orbit now! If you think my post was helpful to you, feel free to press the star icon beside the "Blog this Post" button. It means a lot to me! Happy launching and getting into orbit!