How easy is it to get switched from Reserves to active duty once I get done with all of my training?

Hi I’m currently shipping out tomorrow morning for boot camp I am currently enlisted as a SW in the reserves... I was just curious if anyone could tell me how easy it is to get switched from reserves to active duty once I get done with all of my training? I still don’t know why I chose to go reserves but it’s kinda late to change anything... Thanks in advance!