What happens next?

How to bind your chest
Find out where to buy chest binders.
There are several companies online that design binders specifically for trans men. There are also trans men who sell used binders that either no longer fit or aren't of any use to them.
You may also be able to purchase a binder from your local sex positive merchant. Binders are not only used for trans men but also for males who have gynecomastia.