He can not go wrong with either the .270 Winchester or the .308 caliber rifle.
As he is on a tight budget you might consider a packaged deal ( scope and rifle combination)
Take a look at the Savage Axis EX stainless or the XP in Cammo rifle.
Either rifle is packaged with a Bushnell Banner 3 x 9 power scope (a decent scope for the money) and a detachable magazine.
Both of which are worth your consideration and at your price point as well
Savage has come a long way in improving their products as well as quality.
Don't let the name Savage Axis dissuade you>
I will tell you emphatically that these guns are shooters, and from what I have seen at the range with people using them all in all, they are very pleased with the Savage Axis brand.
In either caliber, ammunition can generally be found in any sporting goods shop that sells ammunition. (pandemic aside)
I own 2 rifles among others that are chambered in 6.5 Creedmoor and IMHO this would be an ideal round for deer provided that you're not in heavy brush or a heavily wooded area.
Additionally, I would not feel comfortable shooting bear unless you had a perfect shot and suggest that you move up in caliber.
See if any dealers in your area carry the rifle and brand that you are looking for.
If you find a dealer who has one get some hands-on and see if it feels right and you like the way it functions.
Now google gun brokers who sell firearms on the internet and find the rifle that you are interested in and check the price from several sites. Once you have the best price you are good to go.
Points to Ponder:
Now if you order online you must have it shipped to an FFL licensed dealer in your area.
Once it has arrived a person over 18, preferably your older brother or Dad can complete the forms and generally if all checks out. you will be able to pick up your rifle after a 3 day wait. ( in my state Florida because I have a concealed weapons permit I can take home my purchase after filling out the Federal forms and waiting for the necessary background check to be completed)
Your State the guidelines may be different for anyone who holds a CCW but generally without one, there is mandatory a 3-day wait to run all your information through the system before you can take your purchase home.
If you plan on purchasing a firearm online and want to use it for this hunting season I would say that is not a likely hood as dealers are behind with shipments as far as 6 -8 weeks.
Once you have your firearm allow time to properly sight it in.
So if you plan on using your firearm this season you may be better, by paying the full retail price and buying at a local gun store.
In this manner, you will have to include a range day and allowing time to zero your rifle as well as familiarizing yourself with your new rifle ( which is a must ) before you take it afield.
The only stumbling block that I see is your age (17). Most states in order to purchase a firearm you must be 18 years of age and complete a firearms safety course. If this is the case in your state you will have to have your Dad, or someone else of age purchase it in their name for you. Now can proceed to take the "Hunter Saftey Course (if it is required) and you're ready for your new rifle to accompany you on its first outing.
Hope this helps!
