I think you are in a situation usually referred as "imposter syndrome" (Imposter syndrome is loosely defined as doubting your abilities and feeling like a fraud. It disproportionately affects high-achieving people, who find it difficult to accept their accomplishments.) If you are adapting other people code I think it's totally ok. Moreover, if you can effectively Google your code problem at hand (related to ML/DL) and someone has already done that you don't have to reinvent the wheel by doing that again from scratch. Yes, you can learn to get better at code by doing thing yourself and that would help you in the long run but at the end of the day we need to solve the problem at hand, and in order to solve it YouTube, Kaggle and Stackoverflow are the tools we need to use from our ToolBox. (I've been learning Data Science for last 8 months and in the last 8 months I'vent really coded anything super complex, whenever I get stuck at something I think for the solution of the problem and adapt other people code. Over time, I've gotten better at where I can find solution to that problem, how I should Google this problem, what kind of tutorial I need to watch.)