I think the conflict causing the confusion here is that stoicism is meant to correct for the emotional mind, and acknowledges that humans are flawed and require over correcting. Stoicism doesn’t say that feelings are bad, but rather are something we can not directly control, and therefore we shouldn’t let them be involved in the rational thoughts of our day to day. A better way of phrasing your quotes is “I would personally prefer x to happen, but I know emotion prefers that outcome over logic, so instead I will pursue y, and will accept whatever outcome happens as fact”.

acceptance.

attachment is the lack of acceptance.

you set goals, visions, dreams.

you identify all the things that could make that true.

you set out to accomplish all of those things.

and whatever happens, happens.

you can be disappointed, but your pain will be temporary. suffering lasts for as long as we remain attached to an outcome, and often grows in intensity

here’s a simplification: ‘i want my parents to live to their 80s’ your dad dies at 50.
it is painful.
you then spend the rest of your days wishing he were still alive, and that he made it to 80. from 30-50, you spend your time attached to the idea that you want him to live until 80. worry, anxiety is the natural thing.

a dramatic example of our illusion of control.

while true we have more control in our lives than if/when someone dies, it’s not by much.

Attach your passions to the journey, not the destination. Do your best according to your current understanding of things, but know that your current understanding is incomplete and delight in the “surprises” of failure that allow you to improve that understanding.

Others have said it really well, but what it boils down to, in every day parlance, is "hope for the best, prepare for the worst".

So certainly work towards your goals, but be prepared to find you don't reach them (incidentally, being resilient like this makes it more likely to reach your goals).