Over the past 7 years I've worked on more than 30 projects, however, I only recently started documenting my work to showcase it.
PDF or website, make sure you have something prepared.
You will not be considered for a UX role without a portfolio. That is a fact. Even if you are a junior. People need to know how junior.
Picking a dream company is very limiting, so the chance of getting rejected from a couple of dream companies is pretty high since the competition for dream companies is quite high. What do you do next in that case. Make sure to plan for that.
Picking a niche or an industry is less limiting, yet still tricky. You might not find enough open positions for the role you are trying to apply in your chosen niche or industry.
Make a list of companies you've applied for and the date you applied. Set a reminder to follow up the recruiter if you get to talk to one.
Not every company is nice enough to give you an update if you have not been chosen for the position. Keep that in mind.