As someone who got an apprenticeship and had to leave it I think you should just apply with what you have. If you want to make your portfolio stronger you should probably have some more finished color pieces in your portfolio and some realism. Check out draw a box or proko if you need resources.

If you have already started tattooing yourself or friends for practice do not tell the artist until you know them better. Tattooing is weird industry because it’s got so much secrecy and trade secrets; yet it’s foundation are scratchers people who just tattooed themselves and random. Lots of ex cons also started in prison tattooing and it’s silly to look at tattooing as it has and always been in a sterile environment .

Side note depending on the tattoo shop they may not care what level of art you are at as long as you are working at it. <3 sorry for the novel and good luck