I've been on 26 cruises so far with #27 scheduled for February 2020. Eastern or Western Caribbean is negligible in difference other than the Atlantic is a bit rougher than the Caribbean UNLESS you hit a storm, which are common in the late winter in the Caribbean.
We've been on most all of the "regular" cruise lines. Not Oceana, Silversea, Seabourn or some other of those. If you want to know which ones they are, google: upscale cruise lines. With that being said, here is MY rankings. Also to consider, I am 55+, retired, but do have teenage kids.
1. NCL
2. MSC
3. Princess
with Carnival, Celebrity, Holland America and Royal Caribbean being pretty equal, but with VERY different price tags.
NCL is my all-time favorite because of their service, cleanliness, food quality (all have food quantity) and price for what you get.
MSC is very European and there are lots of Europeans on the cruise. It is one of the top-ranked cruise lines in and about Europe, so it is familiar with Europeans wanting to see the Caribbean.
Carnival is full of kids.. young kids, middle kids, older kids and usually lots of college age kids that are of the age to drink. They utilize that function extremely well. I explain it as the Walmart of cruise lines....it's for everybody and everybody is on board. Entertainment is kinda cheesy and again, it's for the masses.
Royal Caribbean is about the same as Carnival. They have lots of gadgets on their ships, but I'm not going to go try to climb a wall; I'm not going to play mini-golf, nor try a Wave Rider. I don't want to pay for stuff I'm not going to use. These also attract younger cruisers.
I want peace and quiet, good food, good service, clean areas to lounge around in, some spa time (Extra $$) and a good show occasionally.
My best advice is to get on Trip Advisor and look at the available tours that would be in the locality you might want to go to. This will help you decide on East vs West. They are both good, but some are better for some people. Our crew (6 couples each have favorite ports and they are NOT the same one.)
Now, since you are in Illinois, unless you are going to fly, New Orleans is your closest cruise port. They have some wonderful cruises out of there. The last 3 years, we have gone out of NOLA. It goes smoothly, but not as smooth as in Miami. The other ports, Ft Lauderdale, Tampa and Port Canaveral go as well as NOLA, but not as well as Miami. We have not been out of Mobile, nor Galveston. They have the smaller to medium ships. I like the medium size ships, but the last few have been on the larger ships. They have more people, a few more amenities and usually newer ships.
Any cruise line will be good the first trip, but try out others to see which one fits YOU. Also, if you are going in February, do not go out of NOLA if it is the week of Mardi Gras. LA schools are usually out of school during that week and the ship will be full of young kids. (Ask me how I know!!)
Don't overpack when you go. You will not need lots of outfits. One pair of khaki pants with a couple of golf shirts will work for dinner at night, no matter which line you choose. Change right before and then after dinner and those two will last for a week. I take a black jersey skirt and a couple of tops along with a sundresses that can also be used as a swimsuit coverup. A dressy pair of sandals and I wear a good pair of walking shoes and flip flops to wear around the ship on sea days. I have done this so much that I can pack 8 days of clothing in a backpack that will fit under my seat on the airplane. I then have a large pocketbook for meds, travel papers, passport, etc.
If you have specific questions, you are welcome to PM me.