Guidance on compiling packages

I am running OpenWRT in 32 bits hardware (Alix 2d13 from pcengines) and the image i used is the https://downloads.openwrt.org/releases/21.02.2/targets/x86/geode/openwrt-21.02.2-x86-geode-generic-ext4-combined.img.gz

Since i am running 4 of them with usb 4g sticks (Huawei 3372), i would like to have aome information about connecton status (signal etc) and the ability to send receive sms
I have found some software from https://github.com/4IceG, but i do not have a clue on how to compile it for my architecture

Might I suggest you looking at the "Installation" sections in those repositories....