We need some basic grammar here. The Swahili root -pend- means "like, love". The root -pind- means "bend". The most basic form of a verb is the imperative singular, which is just the root and the most general verb ending -a, so penda means "love/like!" and pinda means "bend!" (addressed to one person). The infinitive prefix is ku-, so you might also see verbs listed with that: kupenda "(to) like/love".
The imperative plural changes the ending -a to -eni: so pendeni "love/like!" (addressed to two or more).
Subjects are indicated by prefixes: nipenda "I love/like", tupenda "we love/like". The second person singular prefix is u-: upenda "you (sg.) love/like". This is the simple or general present, which has no tense marker. Other tenses have a prefix between the person and the verb: ninapenda "I am liking", nilipenda "I liked", etc.
The negative is basically formed with the prefix ha-. The verb ending changes to -i, so tupenda "we love/like", hatupendi "we do not love/like". But there is some merger: hupendi "you (sg.) do not like/love" (for ha-u-), and sipendi "I do not like/love" (for ha-ni-). Note this is a second verb form that can end in -i; the imperative plural (above) is another. As Wazona says, this hupendi is the closest verb form to a supposed 'upendi'. (Or the subjunctive upende "that you may love".) I don't know where The Lion King got that word.
Nouns are mostly formed with prefixes, and abstract nouns usually have the prefix u-. Thus a word beginning with u- could be either an abstract noun or a second person singular verb. When verb roots are made into nouns they often take a different vowel suffix too. Thus the noun "love" is upendo (-o is a common suffix for actions), and the noun "bow" (the weapon) is upinde.