Some things I saved while reading thru Chapter 4: Antennas | The HamStudy Technician License HamBook (2022 - 2026)

4.1 Antenna Types

4.2 Polarization and Orientation

4.3 Feed Lines

Bonus:

The executive summary of the long answer on Microwaves101.Com is that for coaxial cable with an air dielectric, the lowest loss is at about 77 Ω. Air-dielectric coaxial cable can, however, handle the most power when  its characteristic impedance is about 30 Ω. You’ll find all the math at the Microwaves101.Com link above.

Hams want coaxial cables to both handle a fair amount of power and have relatively low loss, so whoever chose 50 Ω as the amateur radio standard did so because it happens to be about halfway between 30Ω and 77 Ω.

Nowadays, we rarely use air-dielectric coax. Instead, we use coax with a polyethylene dielectric. This increases the power-handling capability of the coax. Not only that, a coaxial cable with polyethelene dielectric has the least loss when the characteristic impedance is 51.2Ω.  How lucky is that!

By the way, this line of reasoning also explains why 75 Ω is the standard for video and cable TV. These cables don’t have to handle a lot of power, so minimizing loss is the most important consideration in these applications.

rg213 vs lmr400
I can't tell why these are named as they are. Fun.

4.4 Connectors

This section seems a bit outdated.
Everything I've touched recently is using SMA-F and some micro connector that is not on this list.

4.5 Standing Wave Ratio (SWR)

Standing wave ratio - Wikipedia
Measures impedance match

Mesure SWR with antenna analyzer.
Many modern radios have tools to measure it built in.
Can also use a directional wattmeter?

Checking SWR on a monopole can be tricky?
Uses your body as part of the ground plane?
That's odd.
Apparently actual signal tests are better than SWR measurements for these?
Also there's fixtures to simulate body capacitance?

Someone at the radio nerd meetup had one of these things:
SEESII Upgraded NanoVNA-H4 Vector Network Analyzer, Latest V4.4 9KHz-1.5GHz HF VHF UHF 4" Touch Screen VNA Antenna Analyzer Measures S Parameters,Voltage Standing Wave Ratio, Phase,Delay, Smith Chart: Amazon.com: Industrial & Scientific

I thought about buying one, but I feel like I'd want something that can at least measure 2.4GHz antennas.
I found one, but it was much more expensive.
Maybe there's another way to measure such antennas?