New but not new

Hello,

I'm new to this part of FP but have been using the app for a while. I m trying to gain. I am an extomorph and just can't seem to gain weight very easliy. Now I am in my mid 30's and feel as though I should weigh more than 123 especially for my height. Need any suggestions for weight training I can do at home. I have a fear of going to the gym. TIA