Halochah, Not Mussar
People generally think that the halochos of talmud Torah are mussar-related, and admirable virtues. In truth, just like all other mitzvos, the mitzvah of Talmud Torah has halachos in Shulchan Aruch and other seforim detailing exactly how to fulfill the mitzvah. We all must strengthen ourselves in these halochos.
Every Man is Obligated
Every Jewish man is chayov to learn Torah (שו"ע יו"ד סי' רמ"ו ס"א ) constantly, day and night, according to his ability, as it says: "vehogisa bo yomam volaila" (מג"א סי' קנ"ו סק"ב, שו"ע הרב ס"ה, של"ה שבועות אות כ"א ).
The chiyuv of continuous Torah learning applies to anyone who does not need to occupy himself with his livelihood, or is supported by others, [e.g., Yeshiva bochurim or avreichim], as well as balabatim in the time left after sufficiently providing for their families. Setting aside a bit of time by day and by night is not enough; one is constantly chayov – during all hours of the day and night – according to his strength.
One Who is Preoccupied
One who is engrossed all day in his livelihood or one who is weak or old and cannot dedicate all his time to Torah learning must still set a fixed time by day and by night to learn Torah. As the Mechaber says: "Whether he is poor or rich; healthy or suffering; young or old – even a beggar, and even a man with a wife and children – he must set a fixed time to learn Torah by day and night, as it says, 'vehogisa bo yomam volaila' (שו"ע שם )."
However, when he has spare time, such as after work hours, or when he is unoccupied, the obligation to learn night and day returns (של"ה מס' שבועות אות כ"א ). If he is free and chooses not to learn, he borders on what Chazal say (סנהדרין דף צ"ט ע"א ) on the posuk, "He disgraced the word of Hashem" – "this refers to one who is capable of involving himself in Torah, but does not" (מ"ב סי' קנ"ה סק"ד ).
Extremely preoccupied. If one has no choice and there is a day when he cannot learn at all, he may rely on kerias shema of the morning and evening (מימרא דרשב"י, מנחות צ"ט ע"ב, רמ"א יו"ד סי' רמ"ו ס"א ).
However, realistically, there is almost no one who only has time to fulfill "vehogisa" with kerias shema. This halachah applies to one in a thousand who is an oneis, e.g., on the major market day (שו"ע הרב פ"ג ס"ד, ערוה"ש ס"ז ), or an aveil lo aleinu (ערוה"ש יו"ד סי' ת' ס"ו ).
Doesn't Know How to Learn
One who does not know how to learn at all should still go to the beis medrash and will get schar for going (רמ"א או"ח סי' קנ"ה ס"א ). He is exempt from setting fixed times for learning and is yotzei with learning the little he understands and by supporting others learning (יעב"ץ בסידורו, לימוד אחר התפילה אות ח').
Nowadays, there is almost no one who doesn't know how to learn, as there are seforim in all areas of Torah that are simple to learn, as well as seforim in English and other languages through which one fulfills the mitzvah of Talmud Torah (תשובות והנהגות ח"א סי' תקל"ז ). Therefore, everyone must fulfill their mitzvah by learning what they understand.
"Make Your Work Secondary"
A working man. One should always make his Torah primary and his work secondary; he should minimize his dealings and engage in Torah; he should remove indulgence from his heart... (רמ"א יו"ד סי' רמ"ו סכ"א ), i.e., he should engage in work only to the extent necessary to provide himself and his family with their needs [not just the bare minimum (ש"ך סי' רמ"ג סק"ז )], but not with unnecessary luxuries. He should always try to find ways to increase his learning and reduce his work.
Unable to learn a lot. All of this applies to one who succeeds in his learning and has the strength to learn a great deal. One who is incapable of learning a lot, whether due to lack of intellect, abilities, or focus, does not need to make his work secondary; he is yotzei by just setting some time aside. He may engage in his business the rest of the day to enable himself to amply support talmidei chachomim or his children who are learning Torah, and it is considered as if he himself learned (שו"ע הרב פ"ג ס"ד ).
