I would like to know how possible it is to upgrade form ODK Central client (v1.1.2) and server (v1.1.1) to latest versions of 2024.2 without loss of data. If it is possible, are there any outlined steps to take? Thanks.
See https://docs.getodk.org/central-upgrade for how.
Start by reviewing upgrade notes for all versions between your current version and the one you are upgrading to. You will directly install the latest version but you must follow all upgrade instructions between your current version and the one you are upgrading to. If you are upgrading over many versions, the chance of error increases.
We strongly recommend making all full disk clone and first trying the upgrade on a clone of your production environment to validate the steps that you need to follow.