Help with metemagic

[dnd2016]

New to sorcerer here. I have been using points(5) to up my scorching ray to 3rd, for the extra(2d6) damage. I just realized i could quicken scorching ray for only 2 points to use as my bonus action, and then firebolt for 2d10 damage. Do i have this right?

I am 5th level

[Specter]

Yep. Quicken is one of the best options, spell + cantrip can be massive. Just be careful on its fee (2 points).

[Dalebert]

Some quick thoughts on MM.

Twinned is only for single-target spells but you can twin your firebolt for just 1 point. If fire is your draconic origin element, you can also add cha bonus to dmg. At tier 3, a twinned fb is competitive with a scorching ray. If you also had Quicken, you could do that to scorching ray and then twin a firebolt for some heavy burst damage. Honestly though, Twinned really justifies itself if you're into buffing people like with Haste. I wouldn't get it just for damage spells.

Subtle Spell completely gets around Counterspell and can be useful in a lot of situations. You can leave opponents clueless as to whom they need to attack to break concentration on the polymorph that turned an ally into a tyrannosaurus. You can Detect Thoughts in social situations without anyone being the wiser. If you can get Hex somehow, hexxing someone's wisdom in a social setting gives them disadvantage against your charisma checks which is amazing. Do it to a dragon and combine that with already having advantage and expertise and it's SICK. Every dragon will adore you.

[Citan]

Some quick thoughts on MM.

Twinned is only for single-target spells but you can twin your firebolt for just 1 point. If fire is your draconic origin element, you can also add cha bonus to dmg. At tier 3, a twinned fb is competitive with a scorching ray. If you also had Quicken, you could do that to scorching ray and then twin a firebolt for some heavy burst damage. Honestly though, Twinned really justifies itself if you're into buffing people like with Haste. I wouldn't get it just for damage spells.

Subtle Spell completely gets around Counterspell and can be useful in a lot of situations. You can leave opponents clueless as to whom they need to attack to break concentration on the polymorph that turned an ally into a tyrannosaurus. You can Detect Thoughts in social situations without anyone being the wiser. If you can get Hex somehow, hexxing someone's wisdom in a social setting gives them disadvantage against your charisma checks which is amazing. Do it to a dragon and combine that with already having advantage and expertise and it's SICK. Every dragon will adore you.
I totally agree on the Subtle part. :)
I's be less harsh with Twin though. It really depends on your build. Barring even multiclass, there are several buffs but also debuffs and blast spells making it more than worth it, like Chromatic Bolt, Ray of Sickness, Levitate, Suggestion, Polymorph, Hold Person/Monster, Banishment, Dominate, Disintegrate, etc...
Sure, the proportional cost is a pain, but it's much more valuable on higher level spells (because it costs less than casting then recreating the slot for another cast), not including the action economy. And it mathematically makes you far more prone on succeeding, affecting at least one creature, which is very comforting when you just sacrificed one of these precious high-level slots. ;)