Tu because If you put Mi or mis son rojos it says my are red which dosen't really make sense. Since you put tu in front of son (plual) it would be they are red.
1. todos los años yo invito a mi familia y comemos pastel.
All years I invite my family over and we eat cake.
2. Siempre salimos al centro a ver los fuegos artificiales
We always go to the downtown to watch the lights.
3. La verdad no tengo algo específico que hago cada año pero la mayoría de años he ido a visitar a mis abuelos.
Really I don’t have something specific I do each year but most of the years I went to see my grandparents.
First the day and then the month