Julius Caesar’s success as a politician was deeply tied to his success as a military leader. Therefore studying the Roman army during Caesar’s life helps one understand why he was so popular and why the Senate wanted him dead.
Caesar was commander (or legatus legionis) of the 10th mounted legion, which means his soldiers were mounted on horseback. Caesar was in charge of maintaining control over the warring tribes in Gaul (modern day France). Each legion was organized into 6 companies (cohorts) of 100 men, led by a Centurian, Source : http://thedioscuricollection.com/ejercito_romano_en.php
According to Imperiumromium.com, Caesar helped reform his army, and his Centurians carried out many different campaigns in Gaul:
As you can see, his soldiers were mainly armed with helmets, leather armor, and their large shields and Gladius swords. Below is an exploration of the different parts of the Roman uniform: