Hey guys I'm a beginner, sooner i will buy a flute. I have a question. Is it really necessary to use R little finger for most of the notes. Can we execute the trill without using the right little finger?? thanks.

Hi,
Firstly, I advocate learning the correct fingerings as well as the correct techniques. Some of the fingerings use the RH pinkey to help to stabilize the flute so that it doesn't move around so much and some fingerings require it to be down to get the proper sound...or up. For trills, some fingerings absolutely need it such as D2~Eb2 trill.

Younger players often have the same issue with the LH index finger. It should be up for certain notes such as C#2 and also for the two notes, D2 & Eb2. It helps with the tone quality on them.

I agree completely with Bilbo. On some notes it's not absolutely necessary that you have your pinky down (or up), but on others it is, and you're doing yourself a big disservice not to learn it properly. You'll need to be comfortable doing things properly if you're going to progress.