The trouble with most of what is taught today as exact sciences are pseudo sciences. Even if they can be used for making a living they are still evil. That is psychology, and all it related fields. Obviously they can con people into giving them vast sums of money and have a strong hold over the educational system in the USA even though they have nothing of worth to offer just mirrors and delusions couched in scientific jargon.
People should learn real science and Torah. And when it gets time to get married to learn a honest vocation also.
Torah should be learned thus: a fast session Gemara, Rashi, Tosphot, Maharsha, and Maharam--one עמוד this one side of a page per day. Not a whole Daf. Rather a 1/2 a Daf. That is the fast session. The slow one should be with a learning partner. And that depends a lot on the particular subject.
After one finishes the Talmud then the Ari. (I Luria). But no pseudo Torah. [All supposedly mystic books written after the Ari are pseudo Torah. The exceptions are the books of Yaakov Abuchatzaeia and Shalom Sharabi.]
After one has gone through the Talmud once in the above way, the next thing is to do the Jerusalem Talmud in the same way with all the commentaries on the page. The main thing is to say the words and go on. You will understand much more in this way than if you stayed on every little detail. The you go through the rest of the halachic Midrashim. That is one fast session per day. That takes about 40 minutes if you do it with the Maharsha and Maharam. If you have more time you can do more than a 1/2 a Daf per day. But this seems like a lot already.
There should be another short session in the midrashei hagadah in such a way that after a few years one has finished the entire Oral and Written Law (Old Testament). Every last word. This only seems like a lot because I am not talking about reading novels. If I would say to go through a novel by Tom Clancy in a few days it would seem like nothing to most people. But all of a sudden when it is Torah it sounds like a momentous task.
The slow in depth learning I can give any kind of guidance on. The normal way of going about it is to be in a authentic Lithuanian Yeshiva. You prepare for the Rosh Yeshiva's class in the morning. Then the class is he giving over his original ideas on the Gemara. It is not just reading over some one else's ideas. That is in any case how things were at the Mir. But to get to be able to do this yourself takes more than the regular four years. It might take twenty or more. It is like in the Middle Ages when apprenticeship could last for twenty of more years until one was a master of the art