Look at sites like Digikey
Product Index > Connectors, Interconnects > Rectangular Connectors - Headers, Receptacles, Female Sockets :
https://www.digikey.com/products/en/connectors-interconnects/rectangular-connectors-headers-receptacles-female-sockets/315Product Index > Connectors, Interconnects > Rectangular Connectors - Headers, Male Pins :
https://www.digikey.com/products/en/connectors-interconnects/rectangular-connectors-headers-male-pins/314Product Index > Connectors, Interconnects > Rectangular Connectors - Board Spacers, Stackers (Board to Board) :
https://www.digikey.com/products/en/connectors-interconnects/rectangular-connectors-board-spacers-stackers-board-to-board/400Product Index > Connectors, Interconnects > Rectangular Connectors - Board In, Direct Wire to Board :
https://www.digikey.com/products/en/connectors-interconnects/rectangular-connectors-board-in-direct-wire-to-board/317(and other categories)
Filter by the pitch you want ... you probably want 2.54mm (0.1") for breadboard friendly projects, 2mm for connectors that are still hobby solder friendly but using less space .. maybe 3.96 mm for higher currents
On Digikey you can also see what's more common just by clicking on a pitch size or a value in another section ... you'll see the number below near the "Apply Filters"
For example for the first category I linked to (receptacles, female sockets), you see:
1.00mm : 4,009 results
1.27mm : 29,105 results
2.00mm : 53,624 results
2.54mm : 121,227 results
For the 2nd category , headers - male - pins you have
2.00mm : 31,549 results
2.54mm : 216,576 results
Then maybe order by the amount of units in stock, with the idea that what's stocked in higher quantity is probably what's ordered more often, more popular
For example, sorting the 2nd link after selecting only 2.00 and 2.54mm pitch, i get this:
https://www.digikey.com/short/pzc54zJST PH and PA seem to be stocked in 300k+ quantities, so i guess must be something good about those series if they keep so many in stock
Then you may want to look into connectors that have retention mechanism or not, or if they're friction lock or not... you'll see lots of Chinese products that use cheap connectors and then use thread lock to lock them in place... just because for them it's cheaper than buying a connector with retaining mechanism or for some other reasons (like buying a pump or something from another supplier and that device comes with a connector already installed)