Welcome to RCU, Rcstudent247 !!!
It seems that any picture taken in the North Pole shows up upside down where I live
Yours is a delta that is missing some area in the back.
You could calculate the centroid of each elementary shape and calculate the centroid of the whole plane.
I would go the easy, but not less accurate, way of tracing the half-shape (from the center line of the fuselage including the nose until the wing-tip)) over a flat piece of cardboard.
If you need to scale it down is OK, it works the same.
Then, cut the projected shape so you end up with a flat area that is similar to the half-shape of the wings plus half-fuselage.
Next, you will hand that shape from different points around its periphery and will draw a plumb line for each position.
All the lines should appear crossing at a common point; that is the centroid of the area and that is what any online calculator will find for the area that you enter into it.
A line that is parallel to the center line of the fuse and that is drawn over that point will represent the mean aerodynamic chord (MAC) of that half wing and half fuselage combined.
The length of that line will be the chord of the wind (from leading edge to trail edge including the elevator, if the line runs over it).
Divide that line in four equal portions and mark the location of the leading 25% of that chord.
Finally, your CG should be located 10% of the MAC forward.
This site explains it better than I can: