Is will a subordinating conjunction?
No, will is not a subordinating conjunction. It can either function as a verb (e.g., a modal verb) or a noun (e.g., “Where there’s a will, there’s a way”).
The future tenses (simple future and future perfect etc.) use the verb “will.”
QuillBot’s free Paraphraser can help you find alternative ways of referring to the future time in your texts.