“Les premiers …” is an adequate translation of “the first few …”. We (meaning French speakers from France) wouldn't use “les premiers …” if it can mean a large number of items. The word-by-word translation “?les quelques premiers” is possible if you want to insist that you mean a small number of items, but it's uncommon (contrast frequencies: the first few / few ≈ 1% in English, but les quelques premi(ers|ères) / quelques ≈ 0.003% in French).
To reinforce the “first few” aspect, we might use other words within the semantic field of beginnings, for example:
- “Commencez à écrire les premiers termes de la série.”
- “Nous allons passer rapidement sur le début de la présentation.”
- “Les tous premiers jours seront difficiles.” (Note that this stronger than “the first few”, more like “the very first few”.) (Note that conservative writers write “les tout premiers”, which is somewhat logical because tout is an adverb and thus should be invariable — but the feminine form would be “les toutes premières heures”.)
- “Le résumé doit commencer par quelques phrases résumant le champ d'étude.”