ER to M&A Timeline

Hello all, this is my first post. I've been reading over the past few days on this forum regarding a transition from ER to IBD. Though I was hoping to aim into IBD in terms of M&A, however the headcount at the BB I've accepted an offer for did not have headcount openings.

I've read extensively on how sometimes the transferability to M&A is quite hard or just pretty rare. I've had most of my questions answered via those other posts, however I wanted to ask the community here what the timeline/steps needed would look like for a transfer like such. I am incoming FT at an ER BB, tech coverage. In detail, I hope to understand the networking and recruitment timeline for a lateral transfer or internal transfer to an M&A TMT-based team. (so like when would I start my application process, what would be the most ideal time to transfer, how and when to reach out to recruiters, should I aim for a MBA, etc.) I do realize that I have not yet started on the job, however I have talked to some individuals and I am interested in M&A and I do want to keep the doors open in the event that I still see it more interesting than ER down the line. Thank you all!