I bought my first boat a year ago Memorial Day. Prior to that, I'd ridden in several bass boats but never driven or operated one. So, like you, I had a lot of questions. Unlike you, I wasn't on this forum (or any other) to ask questions so I relied on the dealer to steer me right. Unfortunately, my sales guy didn't have the knowledge I needed so, my first piece of advice is, don't count on the dealer to know everything you should consider. I'm not saying I got a bad boat or a bad deal, because I didn't. I just wish I'd have known then what I know now.
In retrospect, important areas to consider (once you get past the hull type) are:
Storage. Make sure there is plenty of space to store all you need to carry such as rods, tackle, flotation, fire extinguisher, tools, etc.
Engine. How much engine you need will depend on the lake size but, tbh, you can never have too much IMHO. I would opt for the most engine the boat will support.
Trolling Motor. This is a big one. My 17' Lowe has a 45lb thrust, 12v Motorguide on it. It moves the boat and lasts a reasonable amount of time. But, because I fish an electric only lake most of the time, my TM is my primary means of propulsion and I now know that, were I to do it all over again, I would insist on at least a 24v, 80lb thrust TM. I can replace it, but it won't be cheap.
Electronics. I was so excited that the boat came with a Lowrance Hook2 5 in the console. I just knew it was going to help me catch fish. Well, the problem is, I don't fish standing at the console. So I was constantly having to go there to see depth, or ask the back of the boat buddy. consider adding the electronics you want on the bow, whether that's DI, SI or livescope.
Seating. The boat will probably come with a regular seat on the bow. Consider replacing that with a butt seat. It's much easier to lean on when operating the TM than a regular seat.
Trailer. I wish my trailer had self-centering rollers on it. Also, it came with ratchet straps to secure the back. I would replace those with Boat Buckles. You'll be glad you did. Talk about a time saver.
That's just my 2 cents.