Hurricane I think if you're ready and your partner is ready then go for it.
It's not easy living together, ttc, being pregnant or having a baby doesn't matter how old you are.
I was 21 when I had my daughter, she's now 8. A bit older than you but still young. Myself and DH had to rush to move out of our parents houses before our daughter was born so your forward planning is a good idea.
We were financially stable but not well off and had people donate their babies unused items or we bought second hand things. We had everything and most of it we didn't use like the baby bath for instance. It was just easier to use a baby bath chair as I had a c-section as well.
One thing I would prepare yourself for is the judgement of other people. I found being young, I wasn't taken seriously and was viewed as a silly young girl despite me being 21! I was given completely unwanted and unhelpful advice about how to care for my daughter, about routines for her and how to be a good parent. I'd get stared at walking with my pram. I did look very very young for my age so that made it even worse. People would talk to me like I was 15 especially when my daughter started pre-school. By then though I had two daughters under 5.
Quit smoking asap I'd say as well. I quit a year before I fell pregnant but it wasn't because we were ttc, the law changed so I couldn't smoke at work so thought I'd just quit altogether.
Life completely changes once you have a baby, everything revolves around the little squidgy thing that popped out of you.