Recommendations for Simple Contact and Conversation Management App

I am looking for a simple Contact and Conversation management app. I'm not concerned with sales or tasks or things like that. I just periodically have interactions with other professionals in my field and am wanting a way to keep track of who I have met where and what we talked about and how they might be a helpful contact in the future. And I don't really want to clutter up my Outlook personal contacts with this kind of information.

I have been using Zendesk Sell (formerly Base, by FutureSimple) for many years, but they did away with the Free plan after they were acquired by Zendesk, and now, not surprisingly, they are going to delete my grandfathered Free plan in a few months unless I upgrade. And I don't use this service nearly enough for it to be worth one of their paid plans.

Things that are important to me are:

1. Being able to create multiple Notes about a Contact (eg, had a conversation on this date about xyz topic).
2. Being able to assign multiple Categories or Tags to a Contact.
3. Android app that will "sync" with the native phone contact list so that if a Contact calls I'll see their name and not just some number. Offline access would be nice, but not necessary.
4. Being able to BCC and FWD emails into the software to have those stored with any Contacts whose email addresses match, would be nice as well, but I could live without this if need be.
5. FREE, or very low-cost option. I don't use this enough to justify paying very much.

I am open to any ideas or suggestions, including open source options I could install on my own server (I have a GoGeek shared hosting plan with SiteGround). Thanks in advance for any input or recommendations! 🙂