I started playing fiddle when I was 20 years old and have been at it now for a little over 33 years. I began playing paying jobs within a year or so of beginning, and the last 10 or so years have been very busy for me. When I began, I messed around with the instrument for a few months then started lessons with a local guy who was a life long professional fiddle player, who taught using sheet music but also playing by ear. Having taken piano as a kid so I already knew how to read music and used these lessons, a couple of years worth, to develop playing technique.
The single most important piece of advice I can give you is to immerse yourself in the style of music that you want to play. In other words, if you want to play folk music, don't listen to classic rock on your commute to/from work.
My advice to new violinists/fiddle players is to buy an entry level instructional book and get into it. As soon as you've mastered the 1st level, buy the 2nd. By the time you've finished the second book, you'll know beyond any doubt whether or not you want to put the effort into learning the instrument. If you do, then find a good teacher and take lessons. As others have stated, practice, practice, practice. Practicing never guarantees success, but not practicing does guarantee failure.
Regarding a good sounding instrument, it can really be a crapshoot. I've owned more than a dozen through the years and the best I've ever owned and have been playing for over 15 years now, I found at a yard sale in a plastic bag in 5 pieces and paid $5 for it. Stay away from the really inexpensive Chinese violins that have flooded the market. If you know any fiddlers or violinists take them with you to try out instruments as they'll know what to look for in the action, intonation and general set up. Generally speaking an instrument with better looking wood will be of better quality, so look for an instrument with lots of "flame" and figure on the back of it.
Where strings are concerned the options are almost limitless. As with most things, you get what you pay for, but that need only be taken so far. You'll not learn any faster or be a better musician playing $100 strings, but playing an instrument with a good tone builds confidence and encourages playing. I've used Pirastro strings for most of the last 30 years, but many of my contemporaries use D'Addario Helicore's which are moderately price at around $40 and are probably a good place to start.
Finally a bow... It still transcends my understanding that the tone of an instrument varies from bow to bow, but it does! Most new players seem to start out with a fiberglass bow, and I did as well. Bows of this composition are impervious to weather conditions, but most are heavy and akin to bowing with a baseball bat, in my opinion. I'd suggest a decent but not overly expensive carbon bow. When looking at bows of any type, look for a good amount of camber. When the bow is relaxed and held in the horizontal position with the hair down, the body of the bow should touch or nearly touch the hair.
So to FINALLY answer your original question "...what am I getting myself in to?", that is totally dependent on how bad you want to learn and how much you apply yourself.