How do you keep track of all your clients?

I’ve just started as a CSM and I feel like my head and work is complete chaos. I’ve got a bit over 300 clients, which is probably normal, but feels very overwhelming for me.

What are your best tips on keeping track of your clients? I mean practical tips like softwares, apps etc. I’ll take any tips!!

We’re using Microsoft at work (teams&outlook) as well as Hubspot.