What version of open gapps should I get if flashing android 7.1 Lineage Is on my Moto E2 Surnia XT1524
A quick search tells me that Moto E2 runs on Snapdragon 410, which is a typical mid-end 64-bit SoC. However, I investigated its stock ROM and found it's a 32-bit one.
So you should download OpenGApps ARM 7.1 pico in order to get the bare minimum Google Play functionality. You may want to pick another package if you want to have more of Google, but remember to choose ARM from the first column and 7.1 from the second.
According to Andy Yan, if you attempt to flash a wrong OpenGApps package, it will refuse to install and tell you the right one you should pick.