How do I get Mass spectrometry graph, history, and Infra-red spectroscopy graph for Secnidazole?
https://sdbs.db.aist.go.jp/sdbs/cgi-bin/cre_index.cgi (or search sdbs database, it should be the first link) is a useful database that contains a variety of spectral data for a large number of compounds. If you search for Secnidazole, they appear to have MS and IR data for this compound.

If you have access to journal articles, you can also do a literature search for this compound. It is likely that spectral data for this compound will be present in any paper where this molecule was synthesized (either in the main article or its supporting information).

Edit: I just did a brief literature search through Reaxys - most of the papers seemed centered around clinical trials rather than organic synthesis, although I will admit I didn't look over any of them in any great detail.  I'll leave that to you.

Chemical companies such as Sigma Aldrich or Fisher Scientific also sometimes supply spectroscopic data for the compounds they sell.

If you have access to ChemDraw, you can simulate $^1$H and $^{13}$C NMR data for any compound you draw.  I'm sure other spectral simulation programs exist, but don't have much experience in that area.