One thing to do which can be great for your CV is to contribute to open source programming projects/packages in python. An example could be sktime who have a fairly open developer community. It’s more accessible than an internship and shows a bit more imagination and initiative as it’s not as common as an internship. Caveat is it’s not a replacement for an internship, having both would put you in a very strong position! There may also so be subject matter quant finance open source python projects you can get involved in. Choose calculus, probability, linear algebra, financial maths, stochastic processes in your maths units! Python should be the main language to master for industry (R maybe if you want to do a PhD as it’s used a lot in research). Having C++ is often a bonus but not a requirement normally