The car seems to have good speed, and, l could be mistaken here, does not seem to get out of 1st gear (it is automatic) even though l can speed up.Reverse works fine.

u need to replace speed sensor
if sensor bad tran will not shift

if its not getting out of first gear its in limp mode this happens when the transmission senses a problem the computer puts it in to limp mode to protect it,you cant gain much speed in first gear though,and even though it may not slip you cant drive it like this either,have a shop check it,you cant guess at this one,a shop will have to diagnose it for you,good luck.