[LCD-9395 is a PIC-based LCD and is not compatible with the SerLCD library. That is for our AVR serial-enabled displays shown at the beginning of [this Hookup Guide.
To use the old PIC displays, you will want to follow [this guide. The example code in this guide was written for AVR-based Arduinos so you will need to tweak it a bit to work with the RedBoard Turbo. SoftwareSerial is not compatible with ARM-Arduinos but you have plenty of serial ports available to just send the serial data directly through one of those ports. I would recommend taking a look at [this example from the RedBoard Turbo’s Hookup Guide to get started with that code.