For question 2, I would avoid using purpose-driven language, or talk of evolution as some invisible force that meritoriously chooses the best traits (as Naina has used), because that is not how evolution works.
Evolution, most simply, is a change in gene frequency in a population from one generation to the next. There are 4 ways that can occur, but the most important one for us right now is Natural Selection, Darwin's famous discovery.
Natural selection works something like this: imagine a group of furry rabbits, some have more hair, some have less. The ones with more hair have the "hairy" gene, a different gene that makes them have thicker and more abundant hair than their less fluffy relatives. Suddenly a winter comes which is much colder than usual, with lots of snow and very cold air. The rabbits with the "hairy" gene, which are fluffier, survive, because they could comfortably sleep in their dens throughout winter. The ones with little hair unfortunately perished, as they couldn't survive the frigid temperatures. Next summer, the rabbits that mate and reproduce all have the "hairy" gene, and in general have more hair than the previous generation. This is a simplified example to illustrate how it works.
That is natural selection. As you can see, there is no planning, no foresight. The individuals with the right genes in that moment were the ones that transmitted their genes to the next generation. Some individuals were more lucky than others. And as a whole the genes of a population changed from one generation to the next. Some things to keep in mind are that evolution and natural selection don't work on an individual, only at the population level. So a mother rabbit doesn't evolve, or any organism for that matter. Evolution happens because different individuals at any moment have different genes, and some will have more offspring than others. But natural selection is not a random process, actually the complete opposite.
In terms of evidence, there is an enormous amount of evidence. For example, the vestigial limbs in whales, the fossil record, shared DNA sequences among species, or the emergence of antibiotic-resistant bacteria, to name a few.