Check your phone's settings and make sure the language is set to English / your current region. You should be able to install the apps you need by downloading their APK files directly from the Web. It is also possible to change the Sogou keyboard by downloading another one like Gboard.
Normally, using 4G should be possible with this phone. You may configure the phone to only use 3G/4G from its network settings. Unfortunately, it is difficult to give you more specific details as I didn't find any documentation about this phone.
To understand the settings that are written in Chinese, download Google Translate on another phone or tablet, then you can use this app to translate them in English.