Do's and Don'ts after pregnancy. Help.

Hello, My wife tested positive on pregnancy kit today (30 Nov). Clear and dark 2 stripes on Apollo test kits. I read that we should visit doctor only after 8-12 weeks so I am using this platform to ask my query. Query: If someone could suggest me what are the do's and don'ts for the first 3 months, including the lifestyle, diet ( what to eat & what to avoid), medicines etc. She is a vegetarian, eats mostly North Indian food. She is taking folic acid tablets from past 2 weeks. She walks for approximately 3-4 kms, 5-6 days in a week. Patient history: My wife suffered from irregular periods during class 11th & 12th (upto 2-3 months delay) and underwent treatment and got completely recovered. Now after marriage she had regular periods mostly. She used to have pimples, before and during her periods, that too at a same place,  on her chin. She doesn't have any allergies. Her previous periods cycle : 25 October 18 September 16 August 16 July 9 June Kindly help. Thanks in advance.