If you're looking for specific journal IF, it is typically best to look at their website and generally they have it somewhere in "about journal" or similar section. If the journal is any good, they would show it even if it's low. As long as it's indexed actually.
For general list of journals IF, there is another thread:
You can search for a journal, e.g. Nature or anything else you want. When it gives you the journal info, just click on the year you're interested in and it will actually show a list of all indexed journals IFs for that year, which you can search.