What kind of begonias did you buy? I am going to assume tuberous begonias. Check your local nurseries, big box stores, and eBay in spring - they will have plenty of tuberous, wax, and a few other type begonias (canes, rhizomatous). If you want canes and rhizomatous/rex then you may have to buy from specialty growers as they are not "mainstream".

Tuberous begonias have different needs than most other begonias. California and the northern states seem to have better growing conditions for these than Florida and southern states for example.

Enjoy your new begonias and try some other types when you get the chance!

I am new to begonias, and have just picked up my first tuberous this season. I had it in a shady spot with my rexes. It gets a few hours of sun a day. The rexes are happy, but that tuberous has gotten leggy and it does look like the stems could snap at any moment.