Newbie here

The previous person left and we only had a small handover of 2 days (well 1.5 days as they didn't come back after lunch on their last day). One area I’ve been asked to look at is the COSHH as the Managing Director feels it has been a little neglected. I’ve found the COSHH Register and have gone through and can see that we are using some products not listed on there. I’ve spent all of yesterday online trying to find Safety Data Sheets and by the time I went home my head was frazzled, so I’m turning to you wise people for some help and guidance

Where do you get your SDS from?
How do I know when a SDS has been reviewed/updated by the manufacturer?
Thanks so much for any tips and bits of info you can throw my way.