There is a nice round up of open source themed conferences posted at opensource.com:
40 top Linux and open source conferences in 2019
We've rounded up a few favorite picks for conferences to attend in 2019.
Not all of them have specific dates yet. Large conferences are good places to get the latest cutting edge information and to meet a lot of people but I tend to prefer the smaller local conferences both as an attendee and as a presenter.
I am usually at All Things Open and if I travel for a larger conference, I aim for the Security Summit (not on the list) that is colocated with Open Source Summit (which is on the list). Of course, Red Hat Summit is the one where you will find many members of this Learning Community and a great RHCP party.
The LInux Foundation also released there latest 2019 schedule of community events that they help organize and advertise.
I enjoyed the Linux Security Summit that I attended a few years ago and really want to get to another one. Maybe San Diego this summer.