Introducing cats!!

I have a 2 year old munchkin cat that I absolutely adore and he’s very much in love and territorial of me and my husband. Doesn’t like someone else to be in our little circle. But he’s always bored no matter how many toys I bring him and he’s lonely when my husband and I go to work. So I do want to get him a companion but I’m afraid he won’t accept and don’t know how to go about it since I live in a small 1 bedroom apartment. I’ve found a kitten but now I’m hesitant of actually getting it cause I feel like I won’t be able to go through it and won’t know how to introduce them properly. Or that it will cause him to have behavioral issues. He’s actually the best cat ever and I just don’t want to ruin what we have as well. And I know he needs a friend. Please advise!!!