Hopefully I've digested what I've read and heard about 5G correctly, please correct any mistakes.
But a surprise to nobody, the carriers have made a mess of things by branding everything 5G.
AT&T shamelessly just started labeling their 4G network as 5Ge even though it has nothing to do with 5G.
AT&T and Verizon using Dynamic Spectrum Sharing to push 5G out over their existing 4G spectrum. AT&T had been doing this in some areas since last summer it looks like. And Verizon just did it to the entire country when the 5G iPhone 12 launched. Carriers obviously want hide how limited their real 5G networks are. 5G over DSS, is technically 5G, you get the lower latency, but because it's on the 4G spectrum, you are only going to get 4G speeds. 4G LTE and 5G DSS are running off the same towers on the same spectrum. And if there is congestion, the 4G LTE takes priority over the 5G DSS. So if your phone is connected at "5G" you may get slower speeds than someone on an LTE phone.
This is why people have been recommending turning off your 5G if you can, because it just eat more power, and will likely be slower at times. The lower latency not going to have any real benefit to most users at the time.
The real 5G networks, Sub-6 and mmWave, still have a tiny foot print across the country, and is deployed mostly in population dense areas, like sports stadiums and airports. Pretty much anywhere you don't want to be during a pandemic.
At this point I suspect pretty much any 5G phone will show the 5G symbol lighting on in the status bar. But for the vast majority of us, that is almost certainly the 5G DSS running over the 4G network and is no faster and possibly slower.
However back to the original poster's request. I don't want to be a total debbie downer. 5G is coming and maybe he/she is already super lucky has the sub-6 or mmwave coverage.
I probably wouldn't consider the LG phone, that's an older phone, the SoC didn't have 5G integrated at the time, so it's an add-on chip that's definitely less power efficient. It shipped with Android 9 and I don't think LG is that good at updating phones. So this is feeling a tab obsolete already.
The Samsung A71 5G is a good choice. It has the Snapdragon 765G SoC which is designed specifically for what you are looking for, budget 5G phones. So I'd focus on phones with that. Also the Snapdragon 690 is very similar, but the graphics processor won't be as fast.
Pixel 4a 5G is another good budget phone to consider. One Plus Nord N10 if you want to go a little cheaper (it's got the Snapdragon 690).