I just started with android studio just yesterday, it is giving me many errors, adb.exe missing, gradle error, haxm, finally I was able to solve those but now it is giving me these errors:
Render problem failed to find style
and
Could not resolve resource.
I found that I could change compileSdkVersion 27
targetSdkVersion 27 but it did not work. I do not know if it happened to install something, as I say just install it yesterday. I have win 7 and Android Studio 3.1.4 
Well after reading several articles I solved it in this way. I leave it here in case someone comes across these errors.
Go to file > settings > Android SDK, check the box that says show package details, install Android 8.1 SDK platform 27 and Sources for Andorid 27, give it ok. After it finishes updating, in the panel on the right, double click on the build.gradle module app and change the following values: compileSdkVersion 27 targetSdkVersion 27 implementation 'com.android.support:appcompat-v7:27.1.1' implementation 'com.android.support:design:27.1.1' Apparently version 28 is giving problems to some of us, why? I do not know, but that's how I solved it, so if you are installing and using android studio for the first time and you do not have anyone to guide you with the installation, then you can solve it.