The signal
Redstone ore smelts, or drops from witches and chests, into dust. Place dust and it becomes a line. A signal on that line is a number from 1 to 15. Each dust it travels costs one, so a plain line dies after 15 blocks. A repeater listens to a weak end and sends a fresh 15, and it can delay the pulse by 1 to 4 ticks. A redstone torch inverts the signal: on when the block it sits on is off.
Power sources you already own: a lever, a button, a pressure plate, a tripwire, a redstone block, a trapped chest. An observer watches the block in front of its face and emits a short pulse when that block changes. That pulse is how a lot of “automatic” farms notice that a crop grew.
The parts that do work
- Pistons and sticky pistons push blocks. Sticky ones pull the block back. They do not push every block — obsidian, chests and a few others stay put.
- Hoppers pull items from above and push them out the nozzle. Point the nozzle with the sneak-place. A hopper under a chest is a pipe. A hopper pointing sideways into another hopper, with a comparator reading how full it is, is the start of an item sorter.
- Droppers spit items as items. Dispensers use them: arrows fire, water buckets empty, bone meal applies.
- Comparators read containers. A full chest makes a stronger signal than a nearly empty one. Subtract mode lets a signal on the side reduce the one coming through.
What people build
Doors are the honest first project: a button, two dust, a piston, a block. Then a 2×2 piston door, then a sorter that only lets one item type through, then a crop or mob farm that collects itself into a chest. Flying machines are slime (or honey) blocks plus observers and pistons that push their own power source. They are a Java party trick that often fails, or flies differently, on Bedrock.
None of this needs you to be an engineer. It needs you to change one thing at a time. If you place twelve pieces and it doesn’t work, you have twelve suspects.
Java and Bedrock do not agree
Java has quasi-connectivity: a piston can “hear” a power source one block above the block it is attached to, because of an old bug that became a feature. Bedrock pistons do not. Dust on a block, one-tick pulses, and the order in which updates fire also differ. Copy a tutorial from the edition you are playing. The split is explained on the editions page.
On a shared world, a redstone clock left running in a loaded chunk is how you get a message from an admin. That etiquette is on the player rules page.