Jesus did not say, come, be a member of a church....He said,
24Truly, truly, I say to you, he who hears My word, and believes Him who sent Me, has eternal life, and does not come into judgment, but has passed out of death into life. John 5:24
If one has done that you are a member of the ekklesia...the body of believers....the church.
But you have already said you do attend some kind of “church” on Sundays.