Unlock the Laser Minigun:
To get the Laser Minigun plans means finding the Enclave Vault and joining their faction. The Enclave Vault is located in the southeast area of the map. Go to the Waste Dump on the eastern-most river on your map and search for a cave so you are able to begin the Enclave Faction quest. Once you have joined the Enclave by completing their quest which involves solving puzzles, destroying the robot guardian at Sugar Grove and retrieving a tape there you will have proven your loyalty and be able to access the Enclave Vault terminal. The Laser Minigun Plans are available for 1,000 caps.
Unlock 'Rose’s Syringer' Weapon:
This special syringer is able to shoot any enemy, it causes them to become powerful for 1 minute and then afterwards become incredibly weak. To get Rose's Syringer, you will need to travel to the 'Top of the World', an old pre-war resort that is located at the highest point in the snowy mountains and is guarded by a Raider Robot. This weapon is given as a quest reward by Rose.
Saving the Game:
Fallout 76 is a completely online game so you will not be able to manually save your progress, therefore you need to make sure when you do leave the game you go to the 'Main' menu and select 'Quit Game'. This is the safest way to exit the game.
There is junk everywhere and it is all useful so be sure to scavenge it. Regardless if it's a glass bottle, mop, desk fan or another random object of seemingly useless junk it can be turned into crafting materials which can then be used to craft new weapons, repair old ones and add important structures to your base. Your stash box can hold up to 400 pounds of stuff.