i would start with a couple fairly inexpensive thimbles to try out- it will depend on your (style) of stitching to decide which finger you need a thimble on...i've been quilting for years-own a dozen or so thimbles...and never use any of them. they make thimbles to (accommidate long finger nails), ones out of metal, plastic, rubber, leather, some with dimples, some smooth-even little stick on tabs that you peel off a paper & just stick onto the end of your finger where you need it...it's all a personal choice with no right or wrong--but everyone is different and has different needs- start by a quilting practice piece & see----do you need a thimble? if so, what finger do you need it for?- then visit the lqs and try one that fits that finger & practice some more-
some people quilt with frames, some with hoops, some with nothing but their lap- some even use a spoon on the bottom...there are as many different ways to do it as there are people doing it...just dive in (without investing a bunch of money on items you may never use - like my dozen or so thimbles) and pick up what you need as you find a need for it.