best bet, as mentioned is LOW power and i cant stress enough the need to get the very best eye protection you can afford, in case of any accident and get this safety gear covered prior to ANYTHING else, lasers can cause permanent damage much faster than your eyes can register the light ( literally faster than you can blink).... SAFTEY first , triply so if you are still learning ... but other than that , if you are not wanting to solder anything those survival laser kits come all packaged up ( even include the allen key , which is the only tool you need with them ..
you're gonna have to do a bit of thinking on your own. for a first build go cheap. a red diode is not too expensive. think about how you want to power it and what housing to put it in. read the build threads here, someone put a diode and driver in an altoids tin. very inexpensive learning experience for the builder.
But my mother thinks something in an altoids can will certainly explode, AND she saw the warning at the end of the video, gosh styropyro, stop caring do much about our safty, we can't injure ourselves as much if we didn't watch your videos!