Refer to this document for information on upgrade paths to Win 10 from Win 7. The short answer is if you do an inplace upgrade of your existing Win7 system then yes the data should remain the same. However you may lose some settings like desktop icons, options for programs, etc. depending upon where that data might be stored and how. Furthermore some applications may not be compatible and you'll lose access to those applications (and their data potentially). Note however that you'll still have some legacy Win7 stuff on your system (such as some permissions) and this may cause problems for some applications.
If you do a fresh install of Win10 then you won't retain any data. However any Win7 stuff will be gone so there is no chance it'll cause problems with applications.
Personally I would recommend you back up all your data to an external resource or the cloud before you do anything. Upgrading an OS is a big deal and there is always the chance that after upgrading it starts failing or you run into issues that cause you to need to downgrade again. Making a backup of your data is a common disaster recovery approach you should be doing regularly anyway. Upgrading the OS is a good time to make sure you have a current backup, just in case. Note that if you want to keep bookmarks and whatnot you need to export those per browser. If you have your MS account hooked up then you should be able to store a lot of your data either in the cloud (via your MS account) or in OneDrive (which you have some free storage on).
