Should I make a career path or just be open to interesting positions?

I don't really know what I want to do in my career. I finished university one year ago, and I work as a full stack engineer right now, and I'm quite interested in ML. I'm more frontend-facing right now, but I see low returns on spending too much time learning new frontend frameworks my entire career. I'm more interested in becoming a well-rounded engineer, so I feel that there would be higher returns on digging down into the backend more. I have been looking at trying to join some big tech company as a backend engineer, but I just went on an interview for a small tech company which does quite alot of ML with the hopes that they were looking for another ML engineer. Instead they presented me with a broad-scoped data engineer role which sounded pretty cool.

My strategy up until this point has just been to find cool roles where I get to learn useful stuff as an engineer from people who are way smarter than me. Sometimes I think "If I would make a startup, would this skill come in handy?" Is that a poor framework? Should I have a plan? I don't even know if I ever want to make a startup lol. I'm interested in joining big tech, but other than that I'm not really sure. I just enjoy building stuff, and I see this as an opportunity of learning data engineering really well (which I don't know very well), but that is perhaps not a wise career choice? Any guidance on how to think as a new grad is appreciated lol.