Clan Donald has strict policies regarding sept names: if you can't trace your surname back to a particular area (e.g., the West Highlands and Islands of Scotland or Antrim County, Ireland), you won't be considered eligible for membership in the clan society. I would imagine that your surname is fairly common throughout the British Isles (According to Scots Kith & Kin it was also found in Renfrewshire and Berwickshire, outside Clan Donald territory), so you'd need to do some genealogical research to narrow it down. I'm not going to get into the argument of whether you need to be eligible for membership in a clan to wear its tartan except to note that there's no legal restriction on the vast majority of clan tartans.

On the other hand, there's also a Park tartan, STA ref. #2387. It strongly resembles the MacDonald of the Isles tartan. According to the Scottish Register of Tartans, there are restrictions on it, but it doesn't say what they are exactly. On the other hand the registration notes say that it can be worn by any of the name "Park". Presumably there is at least one weaver that is authorized to produce the tartan.