"Quiero muchas flores."
Translation:I want a lot of flowers.
"Lots of" is plural which is in line with the plural of flowers. "Lots" should be allowed. A lot is also fine, but both should be permitted.
Is querer for objects always "to want"? What if I want to say "I love many flowers" - do I need amar because the flowers aren't people?
Most Spanish speakers I've met would probably use "gustar" to say they really like flowers.