Hi and welcome!
My first experience in Jamaica was a large AI in Ocho Rios. I never had the chance to get off the resort, but knew that I had really missed out by not doing so. I wanted to return the following year, so I decided to just go for it. I booked everything for myself, by myself.
For me, Grand Pineapple Negril was a great start in Negril. Because as an "all inclusive" you have airport transfers, basic alcohol and red stripe, and three meals a day (plus some grill choices on request). There are also so hand me down water sports like a hobie cat and SUP.
That said, don't book here expecting a RIU experience. The Grand Pineapple is pretty basic. But that is what I like about it. For a solo traveller, you don't pay more than a double would, you just pay the rate all by yourself- no single supplement. For me, the cost isn't terrible given that there are inclusions.
What I love about the Grand Pineapple as a newbie to Negril, and really, the best part about the Grand Pineapple to me, is the location. You are literally only a few properties away from some of the popular hot spots for visitors and Alfred's is right next door, so going out during the day and night is no problem. Everything is very walkable from the location of the Grand Pineapple.
I also like that I can have a good breakfast in the morning at the hotel, then find my way around town for lunch and dinner. I don't feel like I overspend on the hotel so I don't mind eating out. When I stay at Grand Pineapple, I bring about $400 USD in cash because everything is already paid for before I even get there. That money pays for tips, taxis, excursions, and drinks/snacks/food off property.
For me, Grand Pineapple was a good spring board into Negril. Now, I say at non inclusive hotels and love it, but I'm grateful for giving myself a "back-up" plan with the all inclusive GP. I stayed there again my second year because of returning guest $$ credits. I am struggling with staying there again for my next trip, because it's not much more than a non inclusive hotel I'm looking at and like I said, the location can't be beat for me.
Either way, you can't go wrong in Negril. I would suggest staying at a hotel on the main section of the beach. Walking around, you can't escape the opportunity to talk with people, and if you want, and get a little shy like me when you are 100% on your own, you can just walk to a place, grab a beer, and keep walking ... until you feel comfortable and find places that you connect with.
I love that you are taking a risk and going alone. I think it will change your life! That shyness will leave you in the first 24 hours and you'll have the time of your life!
