You’re absolutely not too old to join the Bundeswehr. Depending on your life situation you could opt to do a FWD (voluntary military service) for at least 7 months or be trained as untrained civilian in the “Ungedient” programme in distinct blocks to not impact your day to day life so much. I would advise to contact your local recruitment office and talk to them, you can get their guidance on your individual situation without signing any commitments.