i want to buy a domain for my blog with number like abcd0.com is it good for seo or not ? and will it effect my seo in the future ?
Don't worry. Domain names have negligible effect towards SERP. Inbound links and onpage-offpage SEO optimization is what really counts!
look at domain names like google and weebly... those don't have anything to do with the contents of their sites and look at the size of them. You just gotta know what you're doing.