I am by no means an expert, but as far as I know, law school is very different in Europe. Usually they start "law school" right after high school and go for 5 years. It isn't something you get an undergrad degree in and then go on to a graduate program. I think that you have to at least get an LLM to practice in the US with a European law degree, but I have heard that it varies from state to state. I have met 2 people with law degrees from different countries (not European ones) that are doing all of their law school over in the US because they can't practice in the US with their degrees plus an LLM.So my recommendation would be to get your degree in the US if you want to practice here.
To practice in the US you one of two things: a foreign first law degree and an LLM in American Legal systems for a very few numbers of states that let you sit for the bar with an LLM, or you can do 2 years of the JD in the US on top of your foreign law degree (and then sit for the bar anywhere) but not all law schools offer this option. Either way you’re going to have to go to law school in the US for at least one year if not more.