Another for the bottle jack.
I bought one of these and I keep it in the back with the spare tire. I've used it twice on my car and once on someone else's. It's worth every penny. https://www.amazon.com/dp/B00GJJZ5YC/ref=cm_sw_r_cp_apa_fabc_otXXFbBKC998Z?_encoding=UTF8&psc=1
Yeah, I had that initial fear back over 22 years when working on my first brake job on my old 1987 BMW 325 and back then there was no Youtube videos on besides the car manual and the old Haynes manual.
For a long time I only worked on two stands or two plastic wheel ramps. Gone through 3 sets of plastic wheel ramps.... Since first one I got.. Only use it for my Bmw since it was a lighter car. Second, I got supported a lot more weight so I got that.. eventually I cracked one accidentally and already gave away my first pair. So I got a third set now and still have it for oil changes and coolant changes. Always exam the plastic ramps for any cracks.
As for jackstands I got two initially, I got those in early 2000 to learn to do brakes and rotors. Again no YouTube videos around... I always supported the jackstands on the indicated and recommended areas of the pinch welds. Always jack up the car where the manual suggests.
My 2005 Toyota Scion tc with 172K miles and original owner has a front jack and a rear jack point that's indicated by the manual. In the past, people always suggested jack up on the rear differential for the rear.... but with todays cars, I decided to play it safe for my 2014 Subaru Outback. So I got these all in one jack stand with built in bottle jack. Note: these will only work if your car is higher off the ground than standard sedans/coupes..
https://www.amazon.com/gp/product/B00GJJZ5YC/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&th=1
Note: you can work on two jackstands fine and have your wheel off and under the car. Also I have chocks for the the rear wheels or front wheels when I work on one side.
Note: Factor in time when jacking up the car and putting on 2 or 4 jackstands.
The only times right now that I use 4 jackstands is only when I rotate my tires and when I change fluids when the car needs to be leveled like your CVT fluid and differential fluids on certain cars.
Those stands from powerbuilt fine to start out on... (actually those don't have the extra pin locking feature, so I would get one with the pin locking feature and sell those off or keep it as back up)
Note Having a wider base will be better and more stable.
Here's a good video on some jackstands comparisons.
A unique jack stand is the Rennstand.
Note: these are very pricey
Other pricey options;
Are quickjacks
Note they have newer models now..
As mentioned I think you are fine sticking with 2 jackstands and a jack.. just follow what EricTheCarGuy says..
Also note, if you want to protect the pinch welds from crushing, you can buy protective pads
like these
https://www.amazon.com/gp/product/B07KFDM55B/ref=ox_sc_act_title_1?smid=AEYNM41RXO3QD&th=1
Update: I noticed that the powerbuilt jack stands that you have from the posted pictures looks like it's missing one extra safety feature that the newer ones have which is the extra separate locking pin for the ratcheting styl jackstands. Maybe that's why your stands were on sale to get rid of the older ones.
Please check on the video: