New business start date
I am not sure if you would be able to deposit a check in your company name into your personal account. Banks require you to show them company documents such as Articles of Incorporation/Organization and EIN letter, before they open a business bank account and permit depositing checks in company name.
You could register a DBA and add it to your personal bank account, but then you would be doing business as individual (sole proprietor), and I am not sure if that is your intention. In any case, you should consult a CPA on questions of taxation, since the answer to most questions will almost always depend on your personal situation.