advice sought for baseball photos


all advice welcome. this is my first baseball keeper (rest are really bad!!)
I havent cropped or made any adjustments as not worth it at this early stage.
I realise background fence needs to go (ie change location but sun was a problem)
Details & my thinking in brackets on how to improve using my 70 - 300 ED.
bright & sunny - ISO 200 (OK?)
AP f7.1 (trying to eliminate background)
1/500 (needs to be around 1/800+)
300mm (what is the 'ideal' FL for this lens when shooting sports?
AF-C and spot metering
monopod (start with tripod?)
Its a long journey for me obviously but thanks for any feedback.
cheers
R2