The verb Haber is never used alone and only serves in conjunction with the past participle to form the perfect tenses.
By itself is only used in the form of Hay (there is/are), Hubo/Había (There was/were)
The conjugations of Haber in present are: he, has, ha, hemos, han (to form present perfect)
The conjugations of Haber in present subjuntive are: haya, hayas, haya, hayamos, hayan (to form present perfect subjunctive
The conjugations of Haber in imperfect are: había, habías, había, habíamos, habían (to form Pluperfect)
The conjugations of Haber in future are: habré, habrás, habrá, habremos, habrán (to form future perfect)
The conjugations of haber in conditional are: habría, habrías, habría, habríamos, habrían