Tummy time

I’m a first time mom. Just wondering How long and often do you guys do tummy time? My girl is 11weeks an I must admit we haven’t done tummy time that much. I’m disappointed in myself because I should’ve been on top of that but it slips my mind. I’m trying to get her in the habit of it now but shit hates it. I feel horrible because this is something I should’ve been doing a lot often and started ASAP. What can I do to make it fun and want her to want to be on her tummy often and longer? And how old was you LO when they lifted there head ?