Even this isn't exactly correct - that would allow you to cast reaction spells on your turn, but the rules do not.
When you cast a ~~leveled~~ spell using a bonus action, the only other spells you can cast on that turn is a cantrip, with your action.
The difference is you can't cast more leveled spells at all, and you can't cast any spells including cantrips if they don't use an action. That last part doesn't usually matter, unless you have multiple bonus actions, or reaction cantrips (which appeared in the playtest of next edition).
Edited to reduce misinformation, left the wrong in place so corrections make sense
Couple of spoilers in that article, admittedly the game has been around for a while but thought I'd mention it in case you're trying to avoid them.