How would I make a script to pick up blocks for example?

So I saw RDC 2017 London Game Jam, and I was fascinated by 'Team Second Place' 's game.

So I saw their character be able to pick up blocks,or JParty for example.

How would I be able to make something like this possible? What do I use and what shouldn't I use?

The game link: https://www.roblox.com/games/962615364/Ice-Wind-Fire

Any help is GREATLY appreciated,

Thanks for reading,

• VoltCode