I am beginner in music theory so please bear with me. I was looking up a document which talks about transposing music and I understand a few things I think about transposing music. But if I, for example, have a sequence of these notes:

    E D# E D# E E D# E F# G# F# G# A B A# B A# B

• how do I determine which key they are in?
• how do I transpose them to a key of D? Is this online tool accurate? https://transposr.com/