Hi everyone! I'm new here.
I work for a non-profit and I am in need of some help or pointers in the right direction. I for one am not a web developer, I am going to school for computer science, but am not that skillful yet.
Okay back on topic, so I work for a non-profit, and I'm working on their SEO for the website. Doing research and figuring out what I need to add to the Drupal site, I contacted our web master, but he unfortunately cannot help anymore, and will relinquish the code and other information to me so I can find another Drupal Dev.
How difficult is it to upgrade a Drupal site that is this old?
How much time will it take?
How much will this cost?

Any and all help is appreciated!

I'm pretty tech savvy and I love to learn about anything and everything. I am also the technology and maintenance director for this non-profit.

CONTEXT: Through my research on SEO I learned I have to have metatags and schema metatags modules for the Drupal site. Our Drupal CMS version is 9.2.4 and in order to use metatags we have to have 10.3 or higher. Webmaster told me about this version conflict that I overlooked during my research, and also notified me that he can no longer do freelance work, due to his new contract with his employer.

1: I am upgrading my Drupal7 to Drupal10 through the D10 UI ( web/upgrade ), when on the "What will be upgraded?“ , its showing the modules like "Automatic Entity Labels, flag, pathauto, simplenews, " are all under the "Modules that will not be upgraded" list, I have enabled these modules in the D10 new site, so my question is why these modules that can not be upgraded or they don't need to be upgraded ? for example, my Drupal7 using flag module to flogged lots nodes, if it won't be upgraded, then all those flogged content will be lose ？ and the auto-entity-labels , if it does't upgrade, then how the D7 node title will be transfer to D10 ? please advise

2: btw : Do I need to enabled the commerce module in D10 to upgrade the D7 commerce setting into D10 ? will all the D7 commerce setting like products will be upgraded to D10 through the default upgrade UI ?

Thank you.

I tried to make a github repository, but I end up going to update the database, that is not a good solution because it overwrites other people work.
What the best aproach for this?