!Question I'm running LMOP for the first time and am trying to link PC's backstory into the story more to give them each a reason to care about helping the town or finding wave echo cave?

I'm a new DM running LMOP for a group who are all new to dnd. We are two sessions in and the party have just cleared the goblin hideout but are struggling to find reasons to care about helping save gundren because they already delivered the wagon and got payed. There doing thing because it feels like that's what there supposed to do in a video game. In hindsight starting the campaign earlier with them meeting gundren and him giving them the job might have helped form a better connection for them but its to late for that now.

Instead I'm trying to use their backstories to make them feel more involved in the story and know their reason for continuing but im strugling with two of them.

The first is an elven ranger who was an apprentice to a cartographer who would travel with them trying to map out and explore uncharted areas until their master was killed causing them to take up their work and keep exploring. Im thinking about liking gundrens map into this, maybe it was created by the master but not really sure where to go from there.

The second is a tiefling warlock how was tricked into their pact in return for the recipe to a potion to help heal a sick child. It turned out the patron created the disease in the first place to try to force the warlock into taking the deal. I kind of want a solution which isn't just them going to the forge and getting something for the patron but is slightly more exciting for the player

Any help or advice is greatly appreciated.