My life is rough, it's had tacks in it and also splinters, we have hardly any money, food, and chances.
The line "My Life ain't been no crystal stair," to me means that the narrators life has been rough. It also means that her life hasn't been the brightest or the best she's might've faced lots of rough challenges or times. I think it means this because if shes saying her life is not like a crystal stair then it wouldn't be bright, smooth, or nice.
The line "it's had tacks in it" to me means that her life hasn't literally had tacks in it but its' been very hard or something is stopping her from living a better life. Just like a tack something is poking or stopping her from living a good life where she can be happy and not worry about anything bad.
The line "i'se been a climbing on" doesn't literally mean that shes climbing a ladder, stairs, or mountain but it does mean that she is still trying her hardest no matter what circumstance or what situation she's in. This also means that she is not giving up, it shows that one of her character traits is perseverance.
The line "For i'se still goin" means that she is not giving up. Similar to the last one which was im still climbing it means that she is not stopping and if she faces challenges she won't let them stop her or defeat her. This shows that she is very strong and never gives up, she shows lots of great character traits.