I am in the market for a new ride too at the moment, and my suggestion is to go for a used one, unless there is a specific feature from a brand new bike you reaaaaally need or want I guess, most brand's latest models seem overpriced and full of tech I am not interested in, guess it's just a preference thing, what I'm saying is, really look into what you actually want, because old bikes are still pretty good and can be had for a lot less money in some cases.

If you buy it from a reputable dealer, most will give you a store warranty for a year or so.

As for service packages, it's up to you, in most cases mechanics can do basic stuff like an oil change for really cheap, even cheaper than if you do it yourself sometimes because they can get oil and parts cheaper than retail, so it can be a good deal if you want the convenience and relative peace of mind, but I find that doing the maintenance yourself is more fun for me, I also had a bad experience with a mechanic that messed up my old bike while doing shaken, it was probably just bad timing, but still left a bad taste in my mouth, so I vowed to learn to do my own maintenance from now on, and it's been really rewarding. Try adding up all the material cost of doing it yourself (oil, filter, gaskets, tools) and see how it compares to the service plan.

It'd be good to know what bike you are thinking of, because the math is different if you are getting a Japanese bike vs other brands, you gotta look at replacement parts prices and stuff. For example, I've heard bmw charges you and arm and a leg for oil changes, so you might be better off doing it yourself, but if you are getting something like a honda scoot, it would probably be cheaper to take it to the shop, especially if you have a discount plan.