If you are looking something to get started with, void rays are a good place to start.
Void Ray rush - 2 gas, 1 gateway, 1 cyber core, 1 or 2 stargates. Save some chronoboost for building the void rays.
VS zerg: Once you can pull this off with the proper timing, it will win you most games against low level zerg players. 1 void ray kills one queen and vice versa. Most zerg don’t think to build more queens when being attacked by air, so unless they run their zerglings into your base and destroy your economy, this is an all in strategy. You need good scouting for this to work, if you are getting zergling rushed, you need to delay the stargates and build an extra gateway to hold them off with zelots.
Vs terran: This is one of the best strategies to disrupt MMM. Here, you only build 1 stargate and 2 void rays. The point of the void rays is limit the terran’s options, force them to go anti air with marines and missile turrets. You transition into 4 warp gate, throw down a twilight council, and get the robotic legs upgrade for your zelots. Your speed zelots with a few sentries using guardian shield will chew through his marines.
Vs protoss: I never go void rays in PvP. However if you find yourself getting void ray rushed, the proper counter is not Phoenixes, it is stalkers and sentries with guardian shield.
4 warpgate - gateway, 1 or 2 gas, cybernetics core, warpgate research, 3 more gateways, transform all to warp gate when research complete.
This is the stock protoss opening and works well against almost everything other than an well played MMM ball. Your army composition is going to vary based on what your opponent is doing and how much money you have. Make sure you keep your scouting probe alive to place a proxy pylon near his base. Keep warping units in and send out 8-10 units to harrass. when you get engaged by a large enough force, back off to recharge your shields and reinforce. The point isn’t to kill your opponent, it is to contain while you get an expansion and tech up.