？
I want to apply for a bank loan, but what do I need to do procedure-wise?
Literal
Bank-loan [object-を] want-to-receive [but-のだけど], procedure [topic-は] how do [if-たら] good [question-の]?
A casual info-seeking question. のだけど (or んだけど) is the explanatory の + けど, used to soften and set up context before an actual question — 'it's that I want to do X, but [here's my question].' Very common opener for requests and questions. どうしたらいい ('what would be good to do,' 'how should I') is a set phrase literally 'what should I do [such that it would be] good.' The full pattern [question]どうしたらいい is the most natural casual way to ask 'how should I go about X?' The final の? is the casual explanatory question ending.