Species does not assign your class

Choosing Elf does not make the character a Wizard.

Choosing Human does not make the character a Fighter.

Choosing Astral Elf does not require a spellcasting class.

Class is selected separately.

Ability scores can create synergy

In the 2014 rules, fixed species ability-score increases can make some combinations mechanically convenient.

A 2014 Elf's Dexterity increase can support a Rogue or Dexterity-based martial character, for example.

That is a bonus, not a class restriction.

Species traits can fill class gaps

A class without teleportation may value Starlight Step.

A martial character may value an innate cantrip for utility.

A character without Perception proficiency may benefit from Keen Senses.

These are examples of complementary tools rather than mandatory pairings.

Duplicated traits can reduce marginal value

If both species and class grant a similar proficiency or ability, part of the species package may be less valuable to that build unless the rule provides an alternate choice.

Check the exact feature before assuming duplicate proficiency turns into Expertise or another benefit.

Later source design is more flexible

Later pre-2024 Fifth Edition species such as Astral Elf use flexible ability-score increases rather than the fixed 2014 Human and Elf model.

That broadens the number of classes that can use the species efficiently without a campaign override.

Build concept first when appropriate

Optimization can be useful, but D&D is a long-form roleplaying game.

A combination chosen because its story is compelling can remain effective when the class's primary ability is built properly through the campaign's normal character-creation rules.