Now that the San Francisco 49ers are about to report to training camp, there are plenty of storylines to follow from the first day through the end of the summer. What is most important to 49ers fans?San Francisco 49ers fans must follow these storylinesLeft GuardThis is the most wide-open starting spot on the roster. There is an argument for three offensive linemen to start for the 49ers at left guard. Connor Colby will get the first chance. However, he got benched after six starts last year. Robert Jones has more experience. However, he is a free agent signing who did not play last year due to a neck injury. Lastly is the rookie, Carver Willis. He has potential, but he is transitioning to the NFL and to a new position. Who takes over at this spot?How improved is the defensive frontThe 49ers' defensive front should be much improved on paper, but will it turn out that way? They are getting Nick Bosa and Mykel Williams healthy. However, what versions of those players will show up? Bosa is getting older, and Williams is still looking to progress. Alfred Collins should take a step forward in his second season, but will he? Lastly, they added Osa Odighizuwa as their biggest move on defense. Does he change the unit? All four spots should be better. IMAGN IMAGES via Reuters ConnectRookie ProgressThe 49ers did not swing for the fences on some of their rookies, which means they wanted them to get on the field in specific roles as rookies. De’Zhaun Stribling was signed to take some of the load off from losing Jauan Jennings. Kaelon Black is expected to win the backup running back job that Brian Robinson left. Bryce Huff retired so they drafted a speed rusher in Romello Height. Even Willis will push to start at left guard. If all four of those higher rookie picks can produce early it will be a huge win. Secondary On paper, all five players in the secondary are coming back. Behind that, the 49ers signed Jack Jones and Nate Hobbs at cornerback while also drafting Ephesians Prysock. Meanwhile, they signed veteran safety Ashtyn Davis. Who gets pushed in the secondary?Health The most injured team last year needs to come into the season a touch healthier. Does George Kittle see the field? Do any other stars enter the year with significant questions? If they can get through training camp healthy, the buzz will pick up. Add us as a preferred source on GoogleFollow