Points Reloaded Quest Guide, updates are in progress. https://mgftw.com/wiki/points-reloaded-quests-guide/
You cannot spend money to change your rep, if you meant your rep is -1000, then my recommendation is to not use throwables like molotovs or pipe bombs until your reputation slowly improves.
You might be rushing too far ahead then, if you haven't already, in game, enter the Settings option, Chat Settings, Notifications, and turn on Rep Notifications, with that you can see in chat when you rep increases or decreases.
