Answer by
LeheckaG (1826)
In the U.S.
Most mechanical-engineers usually obtain a four-year bachelor's degree;
from there one can professional-apprentice,
and then apply for a state-license as a professional-engineer.
Alternatively,
one can obtain a two-year associates-degree or technical/trade-school,
and/or union-apprentice,
and then apply for a state-license as an operating-engineer or other similar trade.