Welcome to Connect, @Dilman
Great that you want to start your experience here with one of the most challenging activities: adding roads. There are a lot of topics in Connect about this subject, and also an ongoing campaign that will end at the end of this month.
I suggest you to start from here: 3000+, and counting. My tips for adding roads in Google Maps
At the end of the article there are additional links.
The reviews of the edits are made by a blend of AI and trained operators. The first check is made by the AI, to see if your edit is corresponding to an actual road, that should be visible on satellite mode. If the road is not clearly visible the edit will be immediately rejected
If the edit is still pending you cannot modify it, and adding one more road can cause a big mess. Of it is rejected feel free to edit that road again
Good luck, hope you will enjoy the experience and become one of the Roaders of the community: Roaders At Work - The Hidden Heroes of Google Maps