The top front screw is the trigger stop screw. This controls the trigger overtravel after sear disengagement. Sometimes this is all that's required to blow out leftover assembly grit, or dirt from extensive field use, and can result in a perfectly acceptable trigger pull. Note that the adjustment screws will likely be covered with a locking compound and may not be immediately obvious. If anything is not clear and apparent at this time, or at any point along the way, reconsider taking it to a gunsmith.
Safety is paramount.
Remove the trigger guard assembly, and remove the action from the stock. Cock the bolt in the receiver. There are readily available aftermarket triggers if that is your desire. Apply a light coat of loctite, fingernail polish, or other locking compound to the screw head when done. Then hold the trigger back, and turn the trigger stop screw counter-clockwise until the firing pin falls.