How to get SCI impact factor from other than Journal site
To see if the journal is indexed in SCI or SSCI, you can search from Clarivate's master journal list. Checking the Impact Factor probably require subscription to Web of Science. Alternatively you can directly search for the journal titles in BioXBio or find any article for the journal to see Impact Factor in Scinapse.

(edit: I work with Pluto Network developing and servicing Scinapse.)