It depends, the rules vary by country. Some court houses even have their own house rules. Weapons in particular are very ruleset-specific.

Even without knowing the exact ruleset, I can still give some general advice:

Party composition

• At least 1 (one) lawyer. You can make do with one of your high wis party members, like a wizard, subclassing as one, but this is not recommended. A dedicated defense lawyer lets the rest of your party focus on their own roles.
• In case the rules do not allow purchasing a judge directly, a thief can be useful to discreetly bribe one instead.
• While paldins can be powerful, especially in theocracies with the same religious alignment, many jurisdictions ban the use of their main healing ability, "lay on hands". Note that in the "USA" area, this ability can be used on children with only a slight karma loss, if your reputation with the "ruling class" faction is "liked" or greater.
• The rest of your party composition is up to you, as it depends too much on the ruleset. (for example, 7th edition nerfed bards greatly: bard songs can no longer buff sneak, beatboxing is no longer a valid instrument and non-religious bard music is now classified as satanic)

Solo builds

Not recommended for new players, but can be a fun challenge for when you're more experienced:

• Barter builds are typically pretty difficult to play, often requiring a high lie stat, good connections and lots of gold.
• If your charisma and luck are high, you can try your hand at a speech build. This does still require careful preparation and perk selection. The idiot savant perk is not optional for this build. As the perk benefits greatly from low intelligence, you can use consumables, like lead & reddit to lower it temporarily. Though as this build is typically played with the politician class, intelligence should not be a problem.
• Agility builds are tricky to pull off. The main one requires great investment to pickpocket & disguise. First, reverse-pickpocket an emetic poison into the judge's inventory. When the judge goes to the bathroom, enter sneak mode by crouching and follow them if you're wearing armor or clothes heavier than "light clothing", remove all of it to get rid of the sneak penalty. When they're alone, pickpocket the judges equipment[1]. You should kill the judge now to be safe. If you're doing a zero-kills run for the achievement, you can let the judge be for now, but you have to be quick. Equipping the judge's gear disguises you as a "judges" faction member. Be careful as some members of the audience might be hostile towards the judges faction and your current equipment has low AC. You should now go take the original judge's place and rule in your favor.

[1]: Pickpocketing equipped equipment requires high skill. If your skill isn't high enough, reverse-pickpocket stronger gear to them, and pickpocket their original equipment once they change into their new gear.