I have had a few. In fact, I have three right now, two Gibson oval hole A models from 1920 and a Tele-style solid body.
If I were gonna start all over, I would join the Mandolin Cafe and read the forum threads about Best Mandos for $500, $1000, $1,500, $2,000, etc.
Then I'd go to youTube and listen to those mandolins and see if they sound good to you. Look up Ovation Mandolins and see if you like the way they sound.
Other sound searches could include Gibson A, A1, A2, A3, A4 and A5 models, Gibson F5 model, Eastman, Kentucky, Collings, stuff like that. There are hundreds of boutique builders, too, but take it one step at a time.
A lot mandolins have skinny necks at the nut (1 1/16th, or 1 1/8th( and some don't (1 3/16ths, 1 7/32nds). I can't play the super skinny mandolin necks any more, so a wider neck is a necessity for me. People who come to mandolins from the guitar often like the wider nuts, but some don't. It all depends on your hands!
Figure out what kind of music you want to play. In bluegrass, a mando often performs the job of a snare drum in an ensemble and you need a mando that has a 'chop' to it when you hit hard with a pick. That usually means an F-hole mando with parallel bracing. As much as I love the old Gibson oval hole mandos, you can't get much of a chop with them (the chop turns into a boing!).
Look for used stuff that has a good re-sale value, because if you really dig the mandolin scene, you're gonna wind up with more and more expensive mandos (you can get a professional grade mando for $2,000.00 or, spend $10-12K for a brand new world class mando that will rock your world). Some mandos go for over $100K, even. I'm not advocating big expenditures, I'm just trying to tell you can drop a lot of dough in a hurry if you get the bug.
Whatever you do, make sure that your instrument is well set-up. If it's not, it won't be any fun at all.
Edited: Oh, lessons, look for Mandolin lessons on youTube. Brad Laird seems to be a pretty good teacher. Check out his free lessons along with other teachers and look for a style that seems to fit you.
In closing, remember that mandolin is just like guitar playing, only upside down and backwards. Play mando for a few months and tell me if that doesn't make sense to you.......
Best of luck, Harry/gilded