Job tardiness, resigning without notice or dragging your feet on the job are potentially damaging but so is taking a job that you know you cannot do because
1. Guess what? You will have to do the job. Whether as a short 2 day gig or for much longer and involving detail that you neglected to mention you know nothing about is therefore potentially damaging.
So, think about whether the job is actually one you will be able to do and whether it is not a job that you will struggle in (and probably make a mess of).
2. Yes, you may start the work and bluff your way through in the beginning but you will not be able to hide your deficiencies for long. You might successfully hide key weaknesses and fluke your way once in a while but the deficiency in your knowledge or experience will eventually get found out.
3. You will ruin your reputation in the short or maybe even the long-term because people who knew you in that job will think of you as mediocre. And when they reference you to other future employers it will not be for doing excellent work, being reliable and professional.
Your reputation is a safety net you build out of past employers and other colleagues and is one thing that you do not want to mess with.
4. You will get extremely frustrated and will frustrate others because as an inexpert person you will find yourself asking others what to do all the time (instead of them asking answers from you).
BTW, not that asking is a bad thing but, there is asking and there is being a dependent incompetent.
5. You are wasting your time in a job that you’re not great at when you could be spending that time building an excellent reputation somewhere else.
Your professional reputation matters and a good one means that when you need to find work, you’ll have the security of knowing that you have a network of people who want to hire you or are at least are proud to recommend you.
