Buy a few rolls of a readily available B&W film. Develop according to manufacturer's instructions and evaluate.
Too flat?
develop longer
too contrasty?
developer less
too thin of a negative?
you underexposed, give it more exposure
too dense of a negative?
you overexposed, shouldn’t cause any issues but expose a little less. Too dense just means you need more light to read your negative. Meaning more exposure under the enlarger.
too grainy?
probably because you underexposed and overdeveloped. Give it more exposure and less development. Also try to agitate less during development. If that doesn’t help move to a lower ISO film. That will give you smaller grain.
Buying a bunch of different films and comparing them to each other makes no sense. You’ll need to spend time with each film to learn how YOU have to develop and handle it to get results to YOUR liking.
Developing B&W film is a personal thing. If you have to send it off to a lab that sucks, but you can work around that. Stick to the same lab. That will most likely guarantee consistency in developer and process. Refer to the list above again to make adjustments to your look.
Remember, it says “film for B&W prints” on the box, not “film for B&W scans”. Scanning adds another huge variable to the look of your film images. If your results sucks it might just be the scans. Look a the negatives. Get them scanned somewhere else, scan them yourself or stop scanning and print your film.