I recommend playing through the introduction tutorial, then playing through a default vanilla game and making your own spaghetti base (like we all seem to do our first time) to figure things out your first time through. This helps you to understand the basic game mechanics and helps you to recognize and appreciate when you figure out best practices and better ways to do things later on. After your first full time through, then it might be a good idea to explore other people’s blueprints to get ideas and inspiration for your next time playing through the game.
In the academic world taking someone else's work and passing it off as your own is cheating or plagiarism. However, in the business world (especially in software development) taking the work (or code) that someone else has done and using it to create your own solution to solve your own problem is called appropriation, and it's much more time-efficient than trying to reinvent the wheel and create something from scratch. This is where the concept of open-source software comes from in the first place.
Factorio is an open-world sandbox game where you get to experiment with creating and automating things any way you can think of, and everyone ends up creating their own unique solutions to get there. Occasionally we all come up with something genius we want to keep for future reference and share with the world, which is the whole reason blueprints were added to the vanilla game in the first place. While building and figuring things out is fun, sharing, collaborating and learning from others is fun too. Learning doesn't have to be an individual experience, there's wisdom in learning from the experience of others.
I recommend avoiding using other people's blueprints if you:
- Don't want to.
- Haven’t played through the full game by yourself yet.
- Prefer to figure things out and build things on your own.
- Enjoy spending lots of time in trial in error.
- Don't want someone else to doing the design work for you.
- Feel stuck in your game progress.
- Are looking for inspiration for better ways to play.
- Like to learn from and reverse engineer other people's ideas.
- Want to master the concepts of the game more quickly (especially if you have limited time to play).
- Don't want to have to research and test out all the math for optimal production and throughput ratios, or reverse engineer complex circuit logic on your own designs.