Can i get hepatitis b or hepatitis c or hiv by sharing joints or cigarettes with other people , i shared cigarettes and joints before covid, should i get a blood test if that's the case? please help me im so nervous ?

None of these viruses is transmitted by this sort of contact. Don’t worry about it and no need for testing.

While you are not at risk of infections you mentioned, tobacco and weed are detrimental to your health and you should quit using these. Have a healthy diet, exercise 30 minutes/day, drink plenty of water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. For nutrition: http://www.choosemyplate.gov/. Get HPV and Covid vaccines. Wish you good health!