A prospective Templar would have to present themselves to a chapter meeting of the Order. He would need to declare that he had not pledged himself to another order, that he was of legitimate birth, and that he was of a knightly family. Lying about any of this could see the brother expelled. He would also have to swear his vows of chastity, poverty, and obedience. When he was accepted, the mantle of the Order would be put on his shoulders. He would be told some of the Order's rules, and would learn the rest over time from his brethren.

The daily life of a Templar, like any monastic, would be governed by the canonical hours. Their day would start with matins in the early hours of the morning. After this short church service the brethren would care for their horses and then go back to bed. In the morning there would be three further services. After that, they would have their first meal. A reading from the Bible would be given whilst the brethren ate in silence. Other services would be in the mid afternoon and at six, followed by another meal. After a final service at 9:00, compline, the knights would have to remain silent until the next day. Every day each brother had to say sixty paternosters, half for the dead brethren, half for the living.

When on a military campaign, the Order would do their best to preserve this routine, following the same services, but obviously this would disrupted by combat, marches, and so on.

It's unlikely you would spend much time studying, you may not even have been literate. The Templars were drawn from the knightly class, rather than the nobility like many of the brethren in other orders. Over time the average literacy rate of the Order would increase in line with the education of the knightly class. In between church services they were ordered to repair their equipment, make tent posts, or do any other work 'befits their office'. The brethren were allowed some recreations. They could gamble, but only items that had little or no value (like tent pegs, bits of candles, or worn crossbow strings). They were also allowed to go riding, but not hawking or hunting, excepting hunting lions. Travel was restricted. A Templar was not allowed to enter towns or houses over a day's journey away from his brethren, unless he had permission.

A Templar would have military responsibilities that no brother of a non-military religious order would have. They had to maintain their equipment, care for their mounts, man defences and fight, but this was combined with the religious responsibilities of other monastics, like saying a set number of paternosters each day, observing the canonical hours, and adhering to his monastic vows.

Sources:

Henri de Curzon (ed.), The Rule of the Templars: The French Text of the Rule of the Order of the Knights Templar, translated from the French by Judith Mary Upton-Ward (Woodbridge, 1992).