Does "Soul Eater NOT" have any "Soul Eater" character appearances like Kidd, Maka or Soul?
Yes Kidd, Maka and Soul appear in Soul Eater Not! and they interact with the students of the NOT class, for example Maka in the first episode:
Whilst struggling to climb the large amount of steps leading up to the DWMA, Tsugumi is helped out by one of the students, Maka Albarn, who encourages her to reach the top […]
Quote from Wikipedia
There are several other occasions where they interact but the show is focused on the NOT class students.