We have to distinguish between abstract theory and the practical reality of how things were actually handled.

In reality, what would almost always happen if a baker caught a boy stealing bread, is that the baker would give him a clout around the ear, or a hiding, and that would be the end of it.

Unless the baker specifically chose to go to a magistrate and lay a formal charge, nothing more would happen. If a formal charge was laid, and there were witnesses willing to testify, then it would all be down to the jury.

Juries often acquitted people, regardless of the facts, if they felt that the punishment would be excessive. If the boy was just hungry and stealing bread, it would be a highly unusual jury who would convict him. People tended to use their common sense, according to the age and type of person accused.

Even if he were convicted, he would be sentenced to transportation rather than death, because the value of the bread was only a penny or two, below the threshold for a capital crime.

I can answer a bit of this.

Context: For the Victorian era of England, punishments for crime were severe, as death was usually applied for most crimes and the whole criminal justice system was harsh. There were efforts to try and reduce what was applicable for capital crimes, but it didn't really happen until a bit after the year you mentioned - 1800s. A lot of the reduction was due to the Punishment of Death 1832 which reduced crime to about 60 Source. Given that kind of context, you can start to understand the answer to some of the specific questions you answered.

Would the age of the person (i.e. a child) or gender make any difference to the sentencing?

For that time period circa 1800, no, it would not matter. Children were seen and thus tried as adults, until 1847 where the Juvenile Offences Act changed this so that children under 14 would go through a different court.

Hence, if you were a young male (even as young as a child) and you stole the bread from a shop, which would be considered shoplifting, that would be a capital offence at the time.

What kind of punishment would be expected for different crimes?

The most common punishments were death or imprisonment. Other punishments were physical labour or fines, but I will focus on the first two for now.

• Death: This was usually done by hanging. The type of offences were the serious ones you'd imagine, like murder but also for minor crimes, such as 'picking pockets or stealing food' source.

• Imprisonment: If you weren't killed then you would be imprisoned. Back in those days the prisons were extremely terrible. A famous gaol at the time was Newgate, which you can also read a bit about here. Most prisons were for serious crimes but then it ended up being more of a waiting place for people to get executed or the other punishment of Transportation (sending criminals to America or Australia, the latter which you may be more familiar with).

If it was not the first offence what difference would that make to the way the courts behaved?

Given the context and what I've said above, no, unless it was extremely minor, but typically they were very strict and most did not live to become a repeat offender (if they were already caught once).

Note: I tried not to link to Wikipedia as I am a bit unsure of the rules as it seems like a 'try not to' preference, but there is a lot of interesting information on Wikipedia as well if you want to try reading those as well.