July 19th is the Democratic Primary. Voting occurs at your local precinct polling site. Find your polling place online.
Yes. Early Voting sites will be located around the county and will be open from 7am to 8pm from July 7th to July 14th. The two early voting sites either in, or immediately adjacent to District 3 are at the College Park Community Center (5051 Pierce Avenue), and at the Lanham VFW Post 8950 (8900 Good Luck Road). Here is a full list of Prince George's County Early Voting sites.
Yes. To do so, you must request a mail-in ballot by July 12th and return it by 8pm July 19th. See the Maryland State Board of Elections site to request a ballot online.