Your knight doesn't have to go back to the beginning. In its October 21 launch FAQ, Funktronic Labs says Scramble Knights Online demo progress carries into the October 26 release. Players who spent time finding equipment can bring that character along.
The same FAQ says a squad can contain four players and that all versions support cross-play. Xbox Wire also lists October 26, calling the release Game Preview. Those details make it easier to plan a first session without guessing which platform label means what.
The bit we're interested in happens on the way home from a quest. Scramble Knights sends its trainee adventurers into Terracott, a kingdom of islands, towns and dungeons. After collecting loot, the group returns to make equipment and prepare for another trip. Fishing is on the store page's list of town activities as well. It sounds like somewhere to wait for a friend who's still deciding what to equip, rather than hurry them toward a ready button.
Launch gives players the one-star area, which the developer estimates at about five hours of unique content, along with faction PvP. That's its estimate; we haven't played through the launch build. A larger update is planned for winter after the team deals with launch issues.
Funktronic says the game is a single purchase with no microtransactions. Possible future cosmetics and a founder's pack have been discussed, but aren't current in-game purchase plans.
We'd begin with the ordinary quests and leave the PvP for another evening. Four people already produce plenty of competing suggestions about where to go. Keeping the demo save removes one chore from that first gathering: getting everybody's character started again.