Yes, molte is a feminine form, but it's an adjective, not a noun. To be precise, it's the plural feminine form of molto. Molto is an adjective that is used to describe un uncertain (big) quantity of something. In its singular form, either feminine or masculine, it's translated as very, much; the plural forms are translated as many.
Ho molto coraggio - I have much courage
"Coraggio" is a masculine singular noun, so molto is used here.
Ho molta energia - I have much energy
"Energia" is a feminine singular noun, so molta is used.
Ho molti libri - I have many books
"Libro" is a masculine noun and its plural form is "libri". The plural masculine form is molti.
Ho molte matite - I have many pencils
"Matita" is a feminine noun and its plural is "matite", so molte is used.
When in front of other adjectives, molto doesn't change. The other adjective does according to whether the noun is masculine/feminine, singular/plural.
Questo cane è molto grosso. Questi cani sono molto grossi.
This dog is very big. These dogs are very big.
Hope this helps!