Take a job at an early stage startup?

Is it a red flag to accept a job from an early stage startup on whose linkedin u dont find any other devs on the team? Maybe they are hiring currently. And the hr who called you is also a freelance hr. The company seems more like a guy who started backed by his family or so or dont know.

Should one take up this job? Or not? If you are currently jobless and need a job so career gap doesnt increase is it wise to take up this one? Also they have already mentioned that u will need to work for good enough hours for the first 6 months. So atleast they aint keeping things hidden.

Or they gonna fire after first 6 months? I heard that such kind of esrly stage startups with 2-10 employees or even less on linkedin tend to do that. The hr did mention that she wants to hire someone who is willing to stay for long term like atleast 3 years. I personally want to work for the next arpund 1 year or so until i can grab a better offer. That way atleast i'll earn the money, there wont be any increase in gap in resume. And i will get to hands on work as well in the industry.

Is there any downside to this? Can it cost me like early firing/termination or anything weird?