I liked the first "Beetlegeuse/Beetlejuice" I watched in my teen years; however, some scenes were bizarre. I had to rewatch it right before the premiere of "Beetlejuice, Beetlejuice" and understood many of the catchy parts and enjoyed it even more, though visually it was "meh".
I watched "Beetlejuice, Beetlejuice" at its premiere, and I liked it! So many storylines were well explained, much acting was great (especially Willem Dafoe), some scenes were hilarious, and I enjoyed many references to the first part.
There's a rule that the sequel quite rarely outplays the original. "Beetlejuice, Beetlejuice" is not better than the original but is very close to the same level. You will not miss anything if you haven't watched the first part, but you may enjoy watching the sequel!