An ellipse is given with semi major and semi minor axis. A few other things are needed to be found.

Use the given equation to calculate the velocities at the different points. You just have to determine the distances from the centre of mass (which in this case the position of the sun since the mass difference is so large) to each point.

Can you please check and tell me if the other answers are correct?

Also it's said here m1 and m2. M1 is the mass of the comet what is m2?

m1 and m2 (does not matter which is which) are the masses of the sun and comet. The mass of the comet (lets say m1) is in this case negligeble compared to the mass of the sun and thus $M=m_1+m_2\approx m_2$

The other answers seem correct!