The fact of wearing tights, should not and will not affect the way you feel toward your manhood if this is part of what is worrying you. In my case, and I don't mind about some  dancers who have some fetishm about that specific type of gartment, sincerelly don't give that many thought.  To tell you the truth, I am not conscious anymore about how does my parts might look and how others might look at it.  I have to accept that most of the time I do feel good when some beautiful female partner stairs at me, while I wear my leothards or tights and tells me how muscular or well buildt I look but I don't go further than that.

I will suggest you to start with something dark and maybe a big and loose t-shirt to cover half of you body, but loose tights, that is something you must not try. Tights will become a part of you regular clothing if you become a regular in the ballet world.  In some studios you will be require to use either loose pants (jazz) and/or tights, and in others you will only use tights.  The reason is to let your teacher see how your leg muscles are developing, besides for some steps and some strecht and extensions movements, tights will make you feel more comfortable while performing those.

When the time comes, you will not only get use to tights but to leothards (either high cut or thong) and unitards,  as well and don't forget to use the dancebelts because a male dancer must always one of those during practicing or rehearsing mainly for security and aesthetical reasons. And if your genitalia shows, well, that is part of our  human characteristics and later on people will really won't pay attention to it (well, that depends only if one of the female partners in your studio don't happen to be your girlfriend, like in my case).

Take care.>