I have been summoned! Though I'm a guy, I'll give my .02 on starting toys.
Echoing what has been said starting with a knot or any toy that has any exceptionally large dimensions (super long or girthy toys) isn't the best idea in my eye. Also would be wise to avoid toys with blunt heads, as they can cause some pretty immediate discomfort.
Being rather tight, it's probably be a good idea to have a rather lengthy warmup fingering yourself before using your toy. Stretching yourself is fun, but is just plain uncomfortable if you aren't adequately warmed up.
I've heard females really liking Nox, and a toy such as that, or even the new toy, Echo, would be decent for a starting toy. They both have gradual enough heads, a stimulating curve, and enough girth to work you up a bit while still giving a nice full feeling. All of that, while not being very challenging toys.
That's all technical stuff, but don't forget, a toy that matches your particular affliction (maybe you have a thing for horses or canine or such) can make all the difference. Deep desire and fantasy can have an amazing impact on taking a toy that'd otherwise be difficult. This obviously has its limits, but is something to keep in mind.
For firmness, I'd recommend getting it in medium; it should be pretty good no matter your preference and assessing how you like it will help you establish a preference for future purchases.
Hope this can be a bit of help! And above all, hope you have endless fun with whatever toy you end up buying!
Last edited: Jan 16, 2016