Might be a simple question, but if your new to any machine changing the fluids can be a little daunting,(specialy the first time.) My bike 2009 flht. Complete engine only oil change, (this requires purging all the oil, using a scavanger or similar), is approx 4 Lts. When bike is warm , the most I get out of the bottom oil drain is 2.4 Lts. That means that 1.6 Lts is still in the engine. If this is your first oil change you don't know if the previous owner put the full 4 lts in the first place. If your half a ltr short of 4lts your dip stick will probably be in the ok area.
So , with no scavaging, just drop the oil and measure what comes out, and put that amount of new oil in. Warm bike up , or go for a short ride, let bike sit for a few minutes. Check level , and add if required to have level in the hot zone . Check in morning to make sure no leaks and level is ok in the cold zone. Most fill the oil filter with oil (thats about 100-200 mls), but that should'nt effect anything, just so you know. Thats my 2 cents worth