A D.C. City Council committee approved the city's proposed $1.3 billion 1979 budget yesterday, clearing the way for the full Council to hold its first formal vote on the budget today.

No amendments were made yesterday. However, attempts to reduce or add to the budget are likely today as Council members seek to shape the budget to meet their view of the city's priorities.

Council members may offer amendments that would set aside funds for additional residential property tax relief, to reserve more money for the D.C. public schools above what the mayor has suggested, and an amendment that would spend about $650,000 for new voting machines.

The Council's vote today is the beginning of a series of complicated formal steps by which the city approves the budget. The Coucil must vote on the budget twice before it is sent to Mayor Walter E. Washington.

If the mayor disapproves any portion of the budget, it is sent back to the Council, which can override the mayor's vetoes by nine votes of the 13-member Council.

If the mayor approves the budget, or if the Council overrides his vetoes, the budget then is sent to the White House, from which it is forwarded to the Congress for final action.