If you have to ask this, most likely a 3080ti is way overkill for your needs.

If you have a huge budget to burn for a beginner, buy either one. Nevertheless, I suggest you start with Google Colab or other free services. Then you can get some feel for the kind of hardware you need for the work you want to do.

It will take you a while to get to a point where Colab is not enough. By that time you won't be a beginner anymore and you will be able to wisely choose a suitable gpu (which may well be no gpu at all, maybe a cloud service fits your use case better?)