Clutches are fairly easy to find. You can get the whole assembly from a variety of sources and then just swap out the discs into your own.
This is a 7 disc clutch as an example .
https://www.monsterscooterparts.com/...embly-atv.html
The improved springs are just EBC Part number CSK41.
https://www.amazon.com/EBC-Brakes-Cl...s%2C175&sr=8-1
You may need a new right side cover gasket and an oil slinger gasket so I would just get a whole gasket kit because it never hurts to have other gaskets on hand.
https://www.ebay.com/itm/25353966688...3ABFBMrP69lZxh
You will also need one of these tools -
https://www.ebay.com/itm/17536949637...Cclp%3A2047675
Another highly suggested tool is one you can rent from an auto parts store which is an impact driver. This is highly suggested to remove the 3 screws that hold the cap on of the oil slinger. They are often notoriously tight and very easy to strip out. This is an example of one. It is a handy tool to own but if your buget is tight you can definitely rent some of these tools.
https://www.amazon.com/TEKTON-2905-8...85539586&psc=1
Hopefully you have somebody you can borrow a torque wrench or two from. You will want one that can do inch pounds for some of the smaller bolts like the bolts that hold the clutch springs down since they only take 5ft-lbs/60in-lbs ((China spec) I used 9ft-lbs/108in-lbs which is a Honda spec) and one capable of 60ft-lbs for the oil slinger nut
As far as procedures to do the clutch replacement there isn't really a good video but CSC has a procedure with pictures for the TT250 which is more or less the same process for the Hawk
https://cscmotorcycles.com/tt250-clutch-replacement/
Otherwise you can also watch videos of other motorcycle clutch replacements to help get a feel as the process is very similar for many bikes
The standard Hawk chain is a 428H 130 links
I have a preference for RK or DID chains such as this
https://www.amazon.com/RK-Racing-Cha...s%2C110&sr=8-2
As far as tires go there are quite a few options out there that will work with the Hawk. The real question comes down to your budget.