drip irrigation system/parts needed (North Seattle)

I want to install a drip irrigation system for my veggie garden. Does anyone have leftovers parts? I saw videos on how to DIY and I want to give it a try, but I would like to reduce waste in this world and and save money too. I will appreciate if someone can share parts. that may be sitting unused. I think what is needed is connectors, distribution tubing, tee and elbow fittings, valves, etc. Do you recommend a 1/2 inch or 3/4 inch tubbing? also, should I install a timer? thanks for your help