When planning your career, and looking for opportunities, you should rely on the help that other people can offer. In my experience, most academics are willing to support others. It takes a lot of courage to develop these while being a PhD student. One strategy for this can be to meet someone as part of a small group. I tried to make use of local opportunities, chatting with invited speakers and other guests. Workshops and conferences offer a chance to check for potential hosting labs for independent fellowships. In general, I felt it was as important to speak to people working in a lab and not just the supervisor to get a feel for the atmosphere and fit. However, it can be difficult to make connections. In addition, the reliance on personal connections provides advantages to those who, by luck, have certain connections.
Accordingly, the aim would be to share information people have more broadly. One way where this is happening is social media. Mastodon and Bluesky are places where lots of positions are now being posted. You can use these passively, though I find social interactions there can be a helpful tool in many different ways.
In addition, there are more specific websites where people share information about opportunities. In my field, there is a community driven sheet listing academic positions, email lists, various job boards, and I made a list of independent fellowship funding.
With the importance of other people for your career, both positive and negative (see risks in part 2), you might want to consider how you would fit into a research group or department. This is not just about whether they work on topics that you are interested in, so you have the possibilities for stimulating exchange, but more about the fit and ethics. It can be worth to reach out beforehand to current and former members, to see about the atmosphere and expectations. This is about personal fit: for example, if you are looking at a group for a potential postdoc position, do you want a lot of freedom or do you want advice to learn new skills; are people hired because they bring a particular expertise or are they part of a running team of experts; would you be bullied into performing bad science; do all people have equal chances; what are the evaluation criteria that are being used to determine whether a contribution is valuable.
In part 5, I suggest you might want to focus on skills rather than products during your academic career.