  This paper is the first in a series of preparing and analyzing spectral and
other properties for a database of already discovered Changing-Look active
galactic nuclei (CL AGNs). Here, we focus on the spectral fitting and analysis
of broad emission lines in a sample of 93 CL AGNs collected from the literature
with existing SDSS/BOSS/eBOSS spectroscopy where the H$\beta$ emission line
profile does not completely disappear in any epochs. Additionally, we have
gathered older/newer spectral epochs from all the available SDSS data releases
to make the database more complete. We use PyQSOFit and perform a homogeneous
spectral decomposition of all of our SDSS spectra and tabulate the AGN
continuum and emission line properties per epoch per source, chronologically.
This further allows us to categorize the sources in our sample as
\textit{Turn-On} or \textit{Turn-Off} and subsequently check for repeated
occurrences of such phases. We then estimate the black hole mass (M$_{\rm BH}$)
and the Eddington ratio (L$_{\rm bol}$/L$_{\rm Edd}$) per epoch per source
where the required parameters are available and well-estimated. We realize the
movement of the source in the M$_{\rm BH}$ versus L$_{\rm bol}$/L$_{\rm Edd}$
plane allowing us to check for systematic changes in the source's fundamental
properties. We then track their transition along the optical plane of the
Eigenvector 1 (EV1) schema and categorize sources that either stay within the
same Population (A or B) or make an inter-population movement as a function of
spectral epoch. We also test the Balmer decrement (H$\alpha$/H$\beta$) of a
subset of our sample of CL AGNs as a function of time and AGN luminosity.
