Hello Guest
1. 'In search of' means 'looking for', e.g.
'I went in search of a beer.' = 'I went looking for a beer.'
2. 'To search for' means 'to look thoroughly for', e.g.
'I searched for a beer in the fridge.'
You can also say ['search' + object + 'for'], e.g.
'I searched the fridge for a beer.'
3. 'Advice to'/'Advice for'