Are all collar bones suppose to be "level" naturally

and I just have tight trapezius and other upper torso muscles?

or does it vary from body to body?

I'm not quite sure what you mean by "level" but many clavicles appear S-shaped when viewed outside of the body. When viewed while they're still in the body they can appear very differently depending on the development of the bones and muscles surrounding their proximal and distal attachments.

It seems as though you're asking if the distal attachment onto the acromion of the scapula is usually visible as a projection upwards or if it usually lays flat or "level" with the surrounding shoulder structures. If so, then yes many people will have a relatively "level" attachment at the shoulder. However, there are many variations that can occur where the clavicle appears elevated above the shoulder and this can be perfectly normal.

Alternatively, if one were to "separate their shoulder" (tear the acromioclavicular ligament that helps holds this articulation tightly together) then the clavicle can be markedly elevated above the rest of the structures and this is a pathology that can require surgery in some cases.