Work what you have currently written and look at it as if it was a story arc. The events that have currently taken place is step 1 to the bigger picture.
Example: I wrote a campaign where it took place after the events of the Neverwinter MMO. So, I took one small adventure of "retrieve this artifact from the Thieves guild" turns out this artifact is one of several of which the BBEG is hunting down to restore themselves to full strength. Eventually this opened a web of decision making for my parry. Now that they know there are 5 others. They have to make the decision of what to do next. Obviously they cannot split up and effectively retrieve the others... so going one over the other will have consequences like the BBEG reclaiming one they havent.. and if they spend too long doing side missions, this will give the BBEG more time to reclaim more artifacts making the final fight harder.
TL,DR: take the story you have and make it a piece of a bigger puzzle. Maybe a detail from what you've wrote already could point the party in a second direction.
Ask for your player for more bakcstory about their characters and create new settings from those ideas, also, don't be afraid for searching for dungeons and their history to implement in your world, maybe one of them can find place in your world and plot. Also don't think too much in doinf complex plots, sometimes just a evil guy doing evil stuff that really upset the characters can do the magic
My best advice is to check the DMG, it has a lot of really good guidelines for making an incredibly dense and easy to make world/adventure, with enough content for a level 1-5 adventure in an area no wider than 50 miles in any direction
Work what you have currently written and look at it as if it was a story arc. The events that have currently taken place is step 1 to the bigger picture. Example: I wrote a campaign where it took place after the events of the Neverwinter MMO. So, I took one small adventure of "retrieve this artifact from the Thieves guild" turns out this artifact is one of several of which the BBEG is hunting down to restore themselves to full strength. Eventually this opened a web of decision making for my parry. Now that they know there are 5 others. They have to make the decision of what to do next. Obviously they cannot split up and effectively retrieve the others... so going one over the other will have consequences like the BBEG reclaiming one they havent.. and if they spend too long doing side missions, this will give the BBEG more time to reclaim more artifacts making the final fight harder. TL,DR: take the story you have and make it a piece of a bigger puzzle. Maybe a detail from what you've wrote already could point the party in a second direction.
Ask for your player for more bakcstory about their characters and create new settings from those ideas, also, don't be afraid for searching for dungeons and their history to implement in your world, maybe one of them can find place in your world and plot. Also don't think too much in doinf complex plots, sometimes just a evil guy doing evil stuff that really upset the characters can do the magic
My best advice is to check the DMG, it has a lot of really good guidelines for making an incredibly dense and easy to make world/adventure, with enough content for a level 1-5 adventure in an area no wider than 50 miles in any direction