You need to pay more attention to details, you are making a lot of syntax errors and using undefined variable names, for example:
You haven't defined dedomena, you just have defined dedomena_Error and dedomena_correct. Also, you are using invalid syntax to define the aesthetics, no need for this part dedomena_correct$.
You haven't defined g so there is nothing to add to.
See this example correcting your syntax errors (BTW notice how the example is self-contained you should do the same next time)
library(ggplot2)
dedomena_correct <- data.frame(
V1 = c(1, 2, 3, 4, 5, 6),
V2 = c(-1, -2, -1, -2, -3, -4),
V3 = c(1083, 2172, 2742, 2988, 3147, 4218)
)
ggplot(data = dedomena_correct, aes(x = V3, y = V2)) +
geom_point(aes(colour = V2))+
geom_line(aes(V3)) +
ggtitle("Strand bias plot") +
xlab("genome length") +
ylab("genes in strand oriantation") +
theme_classic()

Created on 2020-02-11 by the reprex package (v0.3.0.9001)