Welcome to D*! Not surprising that your old account and pod are both gone. Many have disappeared in recent years.

If you have not already seen the tutorials you may find a read through them helpful!

The real tricks to having fun here on D* are:

• Follow some tags that interest you
• Follow some people who post interesting stuff
• Make some original posts, with pictures where possible
• Join the conversation on other people's posts

and soon you will have many new friends and interesting conversations.

Hello!

Mastodon and Diaspora are both part of the Fediverse, but they're different parts, and users on one cannot follow/interact with users on the other.

That said, many of us have an account on a Diaspora server and another account on a Mastodon server and that works just fine.

Welcome (back) to diaspora*!

As others have already written, diaspora*, Mastodon ("similar to twitter"?) and Friendica ("similar to ... a facebook that twitters"?) communicate more-or-less with each other.
These images from Wikipedia might help?

Personally, I have accounts here on diaspora*, on Friendica, on Mastodon, and on BookWyrm.
Regarding diaspora*, things seem to federate from here to the other instances, but not always in the other direction. Might be pod-dependent (that the pod I'm on doesn't have enough contact with the other instances), might be "skit bakom spakarna" (🙈), might be something else.

I think I like diaspora* most of these ... but I've also been here much longer than on the other ones — I'm still learning how the others work.