Premade adventures—modules—are a great resource for everyone from inexperienced DMs to veterans who could occasionally use lighter fare or enjoy remixing source material. My tips: skim the module, ask players their plans, make a cheat sheet, modify as you please, and religiously keep track of changes.
A tank is a character who can absorb damage without dying and deal consistent damage. They are front liners and protectors. They should be the most accessible target and keep foes from reaching the more fragile party members. Ideally, they can draw fire through abilities and spells.
According to 5e’s basic rules, natural 1s and 20s—before adding modifiers—are the only triggers for critical successes or failures on attack rolls (PBH, pg 195) and death saving throws (DMG, pg 197). Critical success/failure for other rolls is an optional rule.
A round of 5e combat takes 6 in-game seconds; ten rounds make a minute. Outside combat, short rests take an hour; long rests, 8 hours. Chunking time into hours is useful for wilderness exploration and urban activities. For longer trips, days are best. Beyond that, narrative beats set the pace.
Roleplaying is inhabiting a fictional world through a character, taking charge of their actions and expressing their personhood through action. D&D roleplay is a mix of freeform storytelling and mechanical gameplay (aka “rollplay”). Even freeform roleplay doesn’t necessarily equal acting.
D&D Madness isn’t about accurately portraying mental illness. It’s about a fantastical shattering of the mind by the uncanny, weird, or magical. This manifests as short or long-term Madness effects or more-or-less permanent character flaws. There are even variant rules concerning a Sanity Score.
D&D 5e allows you to make a powerful combatant with no arms or armor, and it doesn’t have to be a monk. Fighter and barbarian are terrific options, too, if built right. It takes multiple good ability scores to manage it, though, more so than most builds.
A spellsword is more magically adept than a half-caster, better at melee than most full casters, and not as hardy as a martial character. They move quickly to make the most of good positioning, switching between weapons (often magically enhanced) and spellcasting as needed. A striker, not a tank.
Cursed items are objects of power that negatively affect the user against their will. Sometimes a cursed item provides a tempting benefit along with the negative effect, or it influences the user’s mind to make them unwilling to part with it. Sometimes, the curse doesn’t bother the user at all or can be used to their benefit.
When building a town, you need to have these things in order: Social, Political, Economic, Religious, and Military. Once you have those in order, your town will fill itself out. Let’s take a look.