C.D.
I hate to admit it, but I actually always ask my dad to make the calls for me when I need something done with my car or else I ask him exactly what to say so that when I call I can at least fake some car knowledge! If I don't, I always get that , "Well little lady" garbage that just drives me nuts! From this I have actually learned a few things about cars...
When it comes to an oil change, just ask for the basic. Tell them to change the oil and whatever the house oil is will be fine. Don't let them talk you into a fully synthetic oil unless you want to commit to that for the life of your car. Ones you go full synthetic you can't switch back, and it is VERY expensive!
Ask them to check the fluids and top off anything that needs it. If they come out and tell you that your air filter needs changed, ask to see it. If they say your belt has cracks, don't get it changed yet and ask your husband to look at it. That is a common one they try to get us on!
As for the tire, they have basic features as far as how many miles they are guaranteed for, and you can choose if you want white lettering or not. Go for something reasonably priced with a good warranty and you should be fine. Get an all weather that suits where you live.
Hang in there! It won't be as bad as you think!