Hi, i recently bought a Squier Stratocaster, and it came with a spring, and two L tools ( tools that have an L shape ), I don't know why they came, and the DVD doesn't say anything, can someone help me please?.
the "L" tools are allen wrenches probably...and the spring is for the tremolo I would guess if you ever needed to add tension to it. The allen wrenches are for your truss rod and something else I really wouldn't know on that guitar (possibly to raise/lower the tremolo??). Floyd Rose equipped guitars use allen wrenches for pretty much everything, but I'm not sure about your Squier.
Randall RM100/Basson Cab
DBX166XL/BBE Sonic Maximizer
Boss NS-2, sCream Cheese 2.0 OD, Zakk Wylde wah
Custom Epiphones
Monster Cables
Awe-in-One picks..and more
The springs go in the back of the guitar to balance the vintage tremolo. They are extra as the guitar already has two or three in it.

The two L shaped tools are called Allen wrenches/Allen keys.

They are used to adjust the truss rod, and the action.

They should be different sizes. The larger one should fit the truss rod, on the headstock.

The smaller one should go with the action on the bridge.
You can call me Aaron.

Out on parole, any more instances of plum text and I get put back in...