Using offline bootable installer for my old Dell

I am trying to install MacOS Tahoe on my 10 year old Dell Inspiron 13 7359 (i7 6th gen), and I could not figure out any way to connect it to the internet during the installation process other than using my iPhone as a usb tether device. And internet via usb extremely slows, it shows 29 hours remaining. I am think if there is a way I can use my Macbook Air M4 to create an offline bootable installer, and it that will work in my Dell.

I am a noob with ADHD, and UnPlugged by corpnewt looks too complex to me. Pls help!