Hola  Shoji

The use of the present as in "historic present" brings the past action closer to the listener and create a sense of immediacy, it makes it more real. The usual context is in literature, when there is a narration involving a sequence of events of the type: "Es un día soleado en 1956, se puede ver a la gente pasear por la alameda, los niños ríen, los adultos charlan, ...... ". Another typical use is in biographies where we state important events in the life of someone:  "Miguel de Cervantes nace el 29 de septiembre de 1547 en Alcalá de Henares y fallece el 22 de abril de 1616 en Madrid...."

On the other hand, the present is also used a lot more colloquially when we tell anecdotes or jokes: "... y el hombre va y le dice al camarero...", using the present when we're talking about past events. 

The use of the future and the conditional can also be used with the same functionality in the sense of biographies although I would say that's more unusual to see than the present. Also, they are actions that normally have a previous sentence in the past and we follow that with another sentence in the future/conditional to still state an action in the past but seeing it as a "future" action if we place ourselves on that past moment that we mentioned before. So it's seen as a future within a past. There's the example of the Picasso paragraph in the lesson that says: 

"En 1943 conoció a Françoise Gilot, con la que más tarde tendría dos hijos, Claude y Paloma."

We first use a past tense that places the action clearly in the past, and then follow with a conditional, which is still a past action, obviously, but it's seen as a future action related to that moment when he "met" Françoise Gilot. 

The future or conditional are not used colloquially for anecdotes or jokes like the narrative present mentioned before. 

We will connect the two lessons to be seen at the same time by students - I hope that helps.

Un saludo cordial