Blood meal is usually 13-0-0 so yes it is high nitrogen. It is only good for soil applications, unless you make a tea from it. I've used it in the past and had success. Seagird Guano is a better all around fert though, usually Peruvian is 10-10-2. Also blood meal is very low in PH so if you do use it be aware it may cause other nutes to bind at some point. Yes wait on nutes for at least a few weeks if you are using soil.

best of luck,

Herbus