Possibly.
You might be better off using Web on turn one, and CO the next.
Yes, but you can do that with CO on other turns too.
Also, FS takes multiple turns to deal damage. Possibly leaving the enemy alive am extra xturn when you could of killed it with CO earlier.
If you have a large target that won't drop quickly, possibly with legendary resistance, then FS looks better.
You asked for a better -damaging- spell at 1st or 2nd level. I worked within those limitations to demonstrate that there are other options that are better. You didn't ask for "What combos best with
Chromatic Orb?"
Especially since you can cast
Flaming Sphere, smack someone, block a door, and then cast
Chromatic Orb or other spells on the following turns.
If
Flaming Sphere is maintained for its duration, it is capable of exponentially more damage than
Chromatic Orb can do with a 2nd level slot. It also hits more targets, and can do environmental damage, continuously. Is there a tavern or other wooden structure you would prefer not be there, anymore? Flaming Sphere will reduce it to rubble in 10 minutes or less!
You've found your evil wizard BBEG's tower of knowledge? Bye-Bye spellbooks and historical research beyond what you need to take with you, making it impossible for him to ever know what you stole!
Pretty sure there's a goblin hiding in a haystack? MUAHAHAHAHAHAAAAA!
Flaming Sphere can potentially hit many many more targets, damages objects you need it to, blocks doors and spaces, and lasts a relatively long time in D&D Turn Based Combat in smaller environments. (Obviously it's not great for overland travel pre-casting or anything, but still!)
If you need someone dealt with right this instant and you have to deal at least 4d8 damage to them in one turn to kill them, then yes
Chromatic Orb is absolutely better in that situation. But so is
Sleep.