Ok, first is controls:
You will want to spend most of your time with interact/main/mouse look mode on... you can only interact with the world in this mode, but occasionally something is useful with this mode off. You may toggle this mode with the TAB key.
To move, you may use the wasd or arrow keys. To run, hold shift. To interact, use the right mouse button and left click from the menu, or right click to set a default action which can then be activated repeatedly by left clicking when in the main mode.
To activate anything in game, interact with it. This works with the inventory and crafting stations as well.
You will not often need to attack for now, those are all the combat buttons on your bar. Note, 5 increases run speed, so it can be useful to get places. Also, 7 returns you home, or to a random spawn point if you have no home set. You may assign food to your bar, and other abilities as you gain them.
You may alter keybinds in the options menu (escape.)
So, what to do first?:
Well, now that you know how to move around, you probably want some basic tools. You might want to decide what you want to work on first (skills menu is 'L'.) Each new skill takes 30 in the previous one to unlock, and 60 to go above 30... so you want to master the chain to at least 60 skill.
Basic tools require sticks from any tree (forestry option,) wild plant fiber from grassy areas (nature lore option,) and flint stone from rocky areas (prospecting option.) To craft, right click the stick in your inventory.
Tools:
Axe - logging.
Saw - carpentry, and cutting trees into useful parts.
Shovel - digging/terraforming. Not useful for tunneling.
Pickaxe - tunneling and mining.
Hammer - some construction.
Blacksmith's hammer - blacksmithing (requires rock and comes later on, but figured I would mention it!)
Sickle - farming.
Fishing pole - fishing.
Torch - light.
Sling - ranged weapon rank 1.
knife - more crafting.
Stick and Crucible - forging/smelting.
Cooking pot - cooking.
Cup - drinking.
Notice that you can look at what each requires so long as you have 1 stick.
Stats?:
You can set your stats to increase, decrease, or locked (character screen 'P') so that you can develop the character you want. Each does, of course, have benefits in the end.
After that?:
Start creating something! Work on whatever your chosen area is... and enjoy! You may want to start small, and pay attention to your skill gains, not every task gives equal skill ups.