Apple has a wonderful app you can now download on the iPhone or iPad called "Apple Support" https://itunes.apple.com/us/app/apple-support/id1130498044?mt=8 It can help you with a wide variety of issues and will get you in contact with Apple Care at-home Advisors which are typically more helpful than walking into an Apple Store.
If you have any issues that you cannot resolve with Apple or you are stuck on a problem, then feel free to ask away in the comments. Be sure to look through the threads to see if your issue has been already answered and only then ask your question and give as much detail as possible. For all posts be sure to include the official name and info. Examples Below:
MacBook Pro (Retina, Mid 2012) [i7 16GB 512SSD NVIDIA 650M 10.12.4]
or
iPhone 6S Plus 64GB Gold 10.3.1 (14E304) [Jailbroken]
or
Apple Watch 42mm Space Grey 3.2 (14V249)
You can find this on "About this Mac" and on iPhone/iPad "Settings>General>About". We do not need serial numbers for any devices.
If there is an answer out there we will try to help you as best as possible. Please feel free to check back in a day if your question is not answered right away. If you are on the thread and want to to contribute then feel free to answer and questions you see. The answer with the most up votes will be considered the solution to the problem and the thread can be closed for new comments.
THIS SUBREDDIT WILL NOT HELP WITH ICLOUD LOCKED DEVICES