Proto-Canaanite is the name given to
(a) the Proto-Sinaitic script when found in Canaan.(b) the early Phoenician script before some cut-off date, typically 1050 BCE. The Phoenician, Hebrew, and other Canaanite dialects were largely indistinguishable before that time.(c) a hypothetical ancestor of the Phoenician script, with an undefined affinity to Proto-Sinaitic.
In the case of (c), Proto-Canaanite is generally assumed to have been pictographic, but no such script is attested, and illustrations of it are modern inventions.
References
Proto-Canaanite alphabet Wikipedia(Text) CC BY-SA