There are a few things that are common amongst learning violin and guitar, and there are always a few other things that are helpful to have.
Tuner / Metronome - Beam B01 clip style metronome and tuner ($29.95) or Boss TU30 Tuner and Metronome ($49)
Music Stand - Armour Black Foldable with Bag ($24.95)
Kun Shoulder Rest - 1/8 and 1/4 - 1/2 and 3/4 - 4/4
Wolf Shoulder Rest - 3/4 and 4/4
Picks - Fender - 0.73mm (12 pack) - 1.14mm (12 pack)
Guitar Strap - Lilac Stripe - Black - Blue - Orange - Green