I am getting married soon I wanted to know if men are allowed to wear wedding rings? And second question is are muslims allowed to marry thier first cousins?
In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh
1. According to Shariah, men are only permitted to wear silver rings with the condition that it does not weigh more than 4.374. Any other material or metal other than a silver ring is prohibited for men. 
2. It is permissible for first cousins to marry each other on condition there is no foster relationship between them.
And Allah Ta’āla Knows Best
Checked and Approved,
Mufti Ebrahim Desai.
أقول: ويؤيده نص الحديث السابق من قوله – عليه الصلاة والسلام – «ولا تتممه مثقالا» (رد المحتار، ج 6، ص361، سعيد)