The Electrical lines of forces are virtual concepts. At every point, the direction of the electrical field intensity is tangent to the electric lines of forces. The direction of force applied on the point charge / test charge is along the direction of the electrical field intensity.
If the particle is thrown in any direction, it moves bent like projectile problem in gravity field. Asymtoticaly & ultimately it will move along electric line of forces. Because the perpendicular component of initial velocity will be negligible.
See below pls.
The direction of motion of a charged particle is dependent upon the direction of force being applied on it , which is governed by formula
so the direction of motion of particle is dependent upon the Sign of charge (+ve or -ve) , which will tell us whether it will go along or against electric field .