Tinkering is simply working on projects we enjoy or are curious about. It could be a home improvement project, a newsletter, hosting events, a piece of art, or a software tool. You do what you want, the way you want. You may take pride in showing it, but you aren't doing it for others. And you certainly are not expecting to earn from it. It's mostly for your own pleasure; for the joy and energy of doing and creating.
Entrepreneurship is aimed at creating a sustainable business. You have to deliver solutions that customers want, in the way they want. You need to do a lot of external exploration, test, and pivot often to find the right idea. Even then, you can't just create; you need to do a bunch of extraneous work like marketing, customer calls, research, hiring, pricing, budgeting, fundraising, invoicing, taxes, etc. There's also a lot of uncertainty, pressure to succeed, ups and downs. Entrepreneurship can have fun aspects, but it will also have a lot of not-so-fun parts that are absolutely necessary, especially in pre-PMF stages and if you want to grow it into a large or VC-backed business.
Often people mistake a love for tinkering as a call to entrepreneurship. Tinkering is one part of entrepreneurship, but there are a lot of other parts that tinkerers don't like or aren't skilled at. You can love being a tinkerer, but end up a frustrated and unsuccessful entrepreneur.