Welcome to the community, @Lisa_Wade!
Yes, Airtable formulas can be a bit challenging at first, particularly because they’re not documented very well on the formula field reference page.
In your situation, this is the formula that you would use:
IF(
{Status}!="Complete",
DATEADD({Scheduled Date},275,'days')
)
Note that you don’t have to put the {brackets} around field names with just one word, but I like to do that here to get people in the habit of doing that for field names that have more than one word.
Also, Airtable will never recognize formulas that use “curly quotes” instead of "straight quotes", so always be sure to use straight quotes.
Hope this helps! If this answers your question, could you please mark this comment as the solution to your question? This will help other people who have a similar question. 
Welcome to the community, @Lisa_Wade!
Yes, Airtable formulas can be a bit challenging at first, particularly because they’re not documented very well on the formula field reference page.
In your situation, this is the formula that you would use:
IF(
{Status}!="Complete",
DATEADD({Scheduled Date},275,'days')
)
Note that you don’t have to put the {brackets} around field names with just one word, but I like to do that here to get people in the habit of doing that for field names that have more than one word.
Also, Airtable will never recognize formulas that use “curly quotes” instead of "straight quotes", so always be sure to use straight quotes.
Hope this helps! If this answers your question, could you please mark this comment as the solution to your question? This will help other people who have a similar question.
Hi Scott - thank you. I just had to make an adjustment because if it says “Complete” then it should not do a recall date. You got me over the hump though! Thanks so much.
