I've read about how there were some slave owners who tried to keep slaves still (It wasn't like most of the slaves were reading the newspaper to see the legal changes being made, and even if they did, they could obviously still be beaten or worse for trying to leave.), and that a lot of slaves ended up as sharecroppers in the same place where they were slaves. But in general, did the master or foreman just walk out into the field one day and say "Alright, you're free to go?" Were there enforcement officers who went to plantations to check for slaves or to tell the slaves that they were free?
I think you'll find my answer from What happened to the slaves immediately after the end of slavery in America? especially helpful and relevant here.
Bits I will emphasize here:
Were there enforcement officers who went to plantations to check for slaves or to tell the slaves that they were free?
Kinda, yeah. On June 19, 1865, two months after Lee surrendered at Appomattox, Union General Gordon Granger and ~1800 federal troops arrived in Galveston, Texas. Texas was largely spared from large-scale fighting and had no significant presence of Union troops. When Granger arrived, he read General Order No 3 which declared, "The people of Texas are informed that, in accordance with a proclamation from the Executive of the United States, all slaves are free."
Did the master just walk out into the field one day and say "Alright, you're free to go"?
Again, kinda yeah. In Texas after Granger's arrival, some slave owners neglected to inform their slaves of their change in circumstance until after the end of harvest season.