In November 2023, I gave a presentation and demo about antenna modeling at our MicroHAMs club meeting. This is a fun and valuable topic because there is so much that can be learned by experimenting with antenna models on your computer before building them with hardware and tools.
I recommend getting started with EZNEC available for free here: https://eznec.com (It's available for Microsoft Windows only. Other platforms can run Windows using virtualization.)
My Hustler 5-BTV HF antenna is installed and tuned -- with radials for a ground plane this time. I made my first contact on this new configuration using an Icom IC-7100 in FT8 mode from Washington to Indiana using 10 watts of power. The signal reports included a monitor in Argentina!