Try Casual Breakthrough. It is mostly bots and a lot easier. I too am old. Been playing BF and COD from the very beginning. I still do well but nothing like the good old days. Even though I get hammered I still enjoy playing with the young guns. I just try to find ways to help the team, like serving as a medic or engineer. If you ignore KDR and focus on revives or fixing tanks, it has its own rewards. I think the developers should give more points for revives and support but even as it is, even though most players don't express enough appreciation, I know it is appreciated when you revive, plant mines, fix stuff, etc. Here's a great video that demonstrates this appreciation.
https://youtube.com/shorts/PDzp7GniHaE?si=pahF6LiGtN_sQBjV