Hello,
With changing time everyone move there sites from lower version to Drupal 8 (D8). I appreciate you want same.
In the earlier stage, it is very difficult to move/upgrade the site to D8 because of lack of upgraded module, But thanks to hard work of Drupal community member, this task is rapidly easier than before
Your site is my 16th opportunity to upgrade the site from D8
Normally I have started the work from making a list of the contributed modules and libraries and check their availability in D8.
If I found any of the modules, not present, I immediately talk to the client and suggest the alternative module
After that in install feed module into the site and export all the users, taxonomy, content type structure
Then install D8 using composer(my favorite, direct download also ok)
Import the structure to newly install D8 website.
once done, main challenging work is started, Data Migration.
Enabling the modules Migrate, Migrate Drupal, Migrate Upgrade:,Migrate Plus and its dependent module.
I have faced various challenges, especially two:
1. Upgraded module in D8
2. Upgrade the custom module to D8. earlier version this is an easy task, but in D8 due to changing in naming pattern and file structure of the D8.
I want to know what modules you have used.
Can this possible for you to share this important information with me.
This is the main task, which varies the time otherwise remaining are easy and will be done in short time.
Take your time
Thank You