Step 1: First, the Items
1. A good computer that can run games (there is also ps3 and Xbox, but I would recommend PC)
2. A Steam account (since team fortress 2 is free through steam)
3. (This is recommended, but is not required) a mouse
4. Then the actual game itself
Step 2: Open the Game
1. Go into steam store, and type into the search team fortress 2.
2. Then you will "buy it"(even though it's free) and download it to your computer.
3. There are two ways you can open the game, first is through the desktop, which you simply double click ( it may take awhile to update, considering that it is a big file and updates every so often), the second way is to go into steam, go into your library (towards the top you will see four highlighted words, if you are going left to right, it is the second one) and you will see team fortress 2 on the left, you can double click the name or go an inch to the right and there will be (in blue) a button that says play, and you click it.
Step 3: Run the Game
Step 4: Into a Game
You will then( for this instructable I played capture the flag, but it is your choice, and I am not one judge your decision) click " play multiplayer" and click "play now!"
It will then pull you onto a random server with a random map.
Step 5: Decisions, Decisions...
The next page will give you the map name, what game mode you are playing, and a little bit about the game mode, after reading ( if you did) click continue which is in the same place.
Then you will get to choose a team (click one of the doors, the tv, as it says on the screen, will put you into spectator mode and you will not be able to play, unless you join a team)
You will then choose a class, for this instructable I would recommend the engineer ( since this is what the instructable is about)
Step 6: To the Camping Spot!
Step 7: To Building!
I would recommend placing down the dispenser first, so you don't have to walk back and forth going for metal (metal is what will build the buildings and will upgrade them as well)
A little tip to help the impatient people, hit the dispenser or the sentry gun to speed up the process by a little.
Once it has finished building, it will start to heal you and give you back ammo and metal.
I would fully upgrade that or get it to level 2, then I would build the sentry gun.
The sentry gun will have your back( and possibly shoot it too, if you stand in front of it when it is firing at an enemy) you will want to level both up to level three, that will be the highest level.