To possess, own, or hold.
This two-handed sign is a formal citation. But, either one-handed or two-handed sign can be used interchangeably in daily conversation.
Keep in mind that the verb "have" in English has many different concepts; thus, there are different signs for different meanings on the sentence level.
For example, the English sentence "I can't have you insulting Bob like that", you cannot use the ASL sign, HAVE. Instead, you use the concept: "not accept; refuse to tolerate"; that is NOT+ACCEPT(neg).
Old ASL: this sign HAVE was seen signing by George Veditz in his 1913 film, "Preservation of the Sign Language".
Related signs: RETAIN.
First 100 words.
As you feel more comfortable with the first few hundreds of ASL signs, progress further with your vocabulary and learn signing more.