Should I take the job?

Hey everyone,

Got kind of a weird question here. I am currently working in a Valuations group that solely focuses on 409A valuations. I don't have much experience with financial modeling, as we rely on what management gives us, but I do have a good understanding of comps analysis and DCF. I was offered a corporate and business development analyst role recently, but am worried that I don't have the modeling and Excel skills required to be successful. The last thing I want is for my peers and managers to think that I am a slow worker, don't have the right skills, and regret giving me the offer. I am currently going through WSP's financial modeling and valuation courses, however, they are actually pretty difficult for me and there's a bunch of things I don't have a great grasp on such as modeling a revolver / balancing a model that has issues. 

My question is- should I take the offer knowing that my skills in these areas are lacking (I am willing to put in the time to learn, but as I said, am already finding the content rather difficult since I have never undergone a formal modeling training program and my current role doesn't really require modeling, just basic valuation knowledge), or should I stay in my current role, continuing learning on the side, and maybe another day try and go for corp dev again when I am feeling more confident?

I know it's a bit of a weird question, but I don't want people to think I am incompetent while on the job.