For many users, wifi is not detected right on boot. If you are using a build that is pre Kernel-5.x, you can try and add the grub option "AUTO_LOAD=old". If you are using a newer kernel (5.0+), make sure your device has native support included in the kernel. Some devices may also require the grub option "VULKAN=1" or "GRALLOC=gbm" too.
If it's not working, you can provide your wifi card info to us for help, or you can submit a pull request to our kernel-drivers repo with the proper Linux driver modules for your device ( https://github.com/BlissRoms-x86/external_kernel-drivers ). If you don't know the card name you can try to provide lspci or lsusb (for usb cards) output for us by typing the command into the Terminal (with root)
su lsusb > sdcard/lsusb.txt