Iran is amongst the safest country in the world, next to western European countries.
Tourists cannot be any more welcomed and loved anywhere else than Iran.
Just search in YouTube for “Vlog Iran” then you would see many personal vlogs of tourists that show their love for the country and how they were treated with respect. Iran is one of those countries that tourists are more likely to get pressure to get free things like food than being pressured to buy stuff.
Thousands of tourists have gone to Iran since 2015 and none of them had any issue.
The cases like the Nazanin Zaghari (an Iranian born woman) are very different. She did not go back to Iran because she wanted to visit, she came back for espionage activities and to teach the techniques to create propaganda, which would be used to topple the central government.
Unless you have anything else in mind than simply visiting an ancient land full of surprises, there is nothing to worry about.