This answer is based on my knowledge and research.
May Allah Grant me strength to guide you well, right and forgive me for my mistake
Its good that you make Dua (Allah very much like this act), Well, who don't ask Dua (in sense of arrogance(Ghuroor & Takabbur) ) will consider himself in hell. here some ayat and some more details. link1 Link2
I am giving you small example, I hope you will understand the importance of Dua, Eg: you are ill, and went to a doctor, Dr suggest you some medicine, you bought that but you are not taking those medicine and hoping that i will get fine (which is not possible). same, you are not making Dua and hoping for good doesnot make sense.
As there are multiple time mentioned in Quran & Hadith about dua. and
on daily basis(Tahujjud Time, usually after Isha prayer till morning
prayer adaan time) Allah says, is there any one who has something to
ask(Dua) and I(Allah) will complete (accept) his/her Dua.
So, Effort and Dua are must for each other. Do effort and ask Dua.
Here are some dua's, read its translation