I believe voice lessons are absolutely not necessary (boring) as you could also enter the path by simply singing at your favorite tunes. This the same when you learn an instrument by ear transcriptions only.
You could invest into some devices to help you that way like a
Mic & a
Multitrack Recorder which will authorize you to experiment with
2 parts,
3 parts...
vocal harmonies & another trick regarding this is to turn to
Voice Harmonizers (
hardware or
plugins) which is a good way to
learn &
understand Harmonization... & to sing !
Be able to hear yourself as you sing is the key for any voice correction (try Delays, Loopers...).
Concerning the understanding of
Harmonic Movements needed for your goals you will have to dig into some basic books (Harmonization) & a small keyboard is strongly recommended.
However, if you are a bassist, just a
2 note voicings science (voice leading) on the bass is sufficient to support without any restrictions your singing.
Take it
easy.
