What symbol can I use BEFORE the trademark is issued?

The ™ symbol, or a superscripted TM.

Can I use my last name in my music career if it’s trademarked?

It depends. For example, what is sold with the trademark, and for how long? Are you 14 or 50, and how long have you played professionally?

Can I add the ™ Symbol to my website ?

Definitely Maybe. Trademarks do not protect websites directly. Trademarks protect consumers.