Going outside is great! We loved hikes in a carrier or just stroller walks

Read to him or get him a play mat and see if he will reach and play my cousin started reading and drawing with her twin girls at 3 months and now they are almost 1 reading and talking clear she got them on a set time they read a book to her then they get a snack then they have to draw the letter of the day for her in order to go outside really helps they are very advanced