Max 20 knots on the ground, max 40 knots for winds aloft.
Both figures seem quite high to me, for a student, but we do not know what plane she/he is flying. But above all: one cannot discuss ground wind without discussing its angle with the runway. I would much rather take off and/or land with 30 knots straight ahead than with 20 knots across. Gusting is yet another aspect, especially with crosswind.