My GF is Puerto Rican
Will it be a good idea if I asked my girlfriend to speak ONLY Spanish to me or will that be too overwhelming? Id love to learn Spanish as quickly as possible in the most efficient way. We have a baby boy on the way and I REALLY don't want to be left out of their conversations once he learns Spanish. Any suggestions?
I think it would be awesome to have someone who is fluent in the language to help you learn. You can also practice with her. I wouldn't go full on Spanish yet, but once you get better, start incorporating more of it into your daily conversations. And congrats on the baby!
You need to build a basic speaking foundation first, unless she is a saint she will get frustrated trying to teach you from scratch.
With a baby on the way you have time to build that foundation, use doulingo + an audio course like Michal Thomas. With her helping you will be able to reach the only Spanish at home goal eventually.
I suggest finishing the Spanish course first. By finish, I mean being sure you know most of the content, probably you need to finish the tree and have it gold for a while as a minimum. Your level will probably be around 20 or a bit over unless you're relying mainly on external resources.
You should certainly practice as much as possible until then, but I think it would probably be overwhelming until you have the basics sorted... it's like watching Spanish TV or movies without Spanish subtitles, you need a certain level before it's going to help improve your Spanish, otherwise it's just noise.
I think, that it's actually a very good idea. If you don't understand her, you can always ask her to speak slower or explain some words to you. Unless you don't know a word in Spanish yet - then wait with it at least until you have about an A2 level - which is doable in 1-2 months if you are very dedicated and ready to spend 2 or more hours a day immersing yourself into Spanish.