If i fail 8th grade gym will i fail 8th grade all together?Please help?

Yeah im not rely feeling gym class this year so if i don't participate and fail (witch im fine with) will i fail 8th grade all together and have to repeat 8th grade(witch im not fine with)? Also iv had gym class from first grade - sixth grade then the levy's failed for the 10-11 school season so they cut gym for 7th grade but they passed for the school season coming up so we have gym back and since im in middle school now we have to go and change from our regular school cloths into a uniform for gym do we have to get dressed around everyone else or something.