You may. Sometimes the needed technician is in the local space station but is not flagged with an icon and, sometimes, he's off somewhere else. Do check the "lounge" area behind the technology vendors on the left side of the station (as you face it heading in from space). That's often where the specialists hang out. If you don't get an icon, be sure to interact/talk with every member of the appropriate race. I had to do that to find a Scientist. Annoying but those encounters do add up to one of the achievements. Be sure that you have the appropriate quest selected in your Log. Sometimes the "thing you need to do" is in the list but if it's not the one that's selected then the quest won't advance. But sometimes it does! Better to be safe and select it. As I understand it (happy to get any corrections here!), uploading a base will make it visible to other players while you're on-line. Others can see your base and harvest any plants but they can not remove things from storage or damage the base. Plants that are harvested by another player would still be there (un-harvested) for your use. This is separate from sharing a base/universe in multi-player where, unless you opt to enable restrictions, other players can damage your base (and you!).

You can claim multiple bases; up to 50 (?). Anything that you build inside the base perimeter (a radius of about 150 units from the base computer) will return all resources to you if you deconstruct it. If you delete the entire base all at once by deleting the base computer, you only get back half of the resources.

Since you can craft a teleporter for your base, there's really no urgent need to deconstruct it unless you want to try a different architecture. You can teleport to every one of your bases from anywhere in the same galaxy. If/when you choose to move to a different galaxy (you'll learn how to do that later on), you instantly lose all of your bases in the old galaxy (and can never return) but half of the resources are in a special storage container (which you'll also learn about later). Best when moving galaxies is to deconstruct manually and store the material yourself so you lose less.

Strongly recommend that you start a new game in Creative mode to get a feel for what's possible with base construction. Creative removes the resource restrictions from building and gives you all of the blueprints for components so you can fool around without messing up your normal game. You can have up to five games, so one normal and one creative is fine.