Other than passing a few adventurers and/or merchants, the party will not have any encounters on the main road. Every half hour or so there will be another road or a well-used path heading off in one direction or another. After about six hours the party will reach the path they need to follow.
Have the party roll perception rolls, and use the of the party member with the highest adjusted roll.
You have gotten so used to trees growing up near and sometimes over the road that you nearly missed your turnoff. After passing a pair of red-leaf maple trees, notices that there is a path leading back almost in the direction you have traveled from. They stop and look and notice that the path seems to curve back to the left almost immediately, with the heavy clump of trees preventing the rest of you from noticing the path at all.
The path is only one or two people wide most of the time, so the party should have a marching order at this point. Seriously, you should be using miniatures or at least pieces of paper with character names on them, so place the marching order on the table to help with the encounters.
After travelling along the path for about an hour, the party will have its first actual combat. The party travels around a bend that forces them back into single file, and you should adjust the marching order accordingly, drawing the path and a few large trees to show the limited movement available to them as the move to single file (roll randomly on each pair to determine which character goes first). The last person in line will be attacked when the trees block the view of most of the party.
Pass a note to the person who is last in line telling them that they hear the beating of wings behind them, and ask them to write down their response without speaking out loud. More than likely they’ll turn around; unless they also speak or yell at that point everybody else will continue to walk forward. When they turn around they will see a strange creature that seems to have the body of a lizard, the head of a large bird, and the wings of a bat: it is a cockatrice (but do not tell them the name of the creature).
Cockatrice: Monster Manual page 42
The special attack of the cockatrice can temporarily turn somebody to stone; if this happens the party will have to spend the night at this location since it is difficult to move a stone body. No other encounters will follow until all party members are no longer stoned.
If the party searches in the wooded area the cockatrice came out of, they will find a large nest in a fallen tree that is filled with grass and straw. If somebody searching makes a perception roll they will find some treasure: a plain red gem worth 20 gp and a brilliant but small green gem worth 10 gp.
If nobody was stoned, the party can continue walking through the woods for about two more hours, at which time they will find a small clearing off to the side (if somebody was stoned, the party will have to spend 24 hours at the site of the attack, and will reach this clearing near nightfall the following day. There is a spring pushing water out from between two large stones, and the water travels off to the east, leading to a pond that is about 30 feet across. The party can fish in the pond if they have the proper equipment and can find some blueberry bushes and an apple tree near the pond, or they can simply make do with any rations they brought with them.
Here’s Ray Charles sending the party into combat!