Should I install the Windows 10 preview? I wanna experience windows 10 but I don't want my surface 2 being laggy or irresponsive or anything happening that will make me regret for buying this tablet.
You can't. It is only available for X86/64 devices. Microsoft is not planning on releasing W10 for the Surface RT and Surface 2 but will be releasing a subset of W10 features.
However, if you do mean the Surface Pro 2, then go for it and give feedback. However, only if it's not your main PC. If it is, then just wait until the Consumer Preview (when it's a bit more finished).