Should I buy a stronger CPU with integrated graphics now and add a GPU later?

For schoolwork and Valorant, a modern CPU with decent integrated graphics can be perfectly usable. You could run without a dedicated GPU and add one later when your budget improves. Just make sure the system uses fast, dual-channel memory, since integrated graphics share system RAM. A setup with 16 GB or more is a good starting point.

The best choice depends on how soon you need high gaming performance. If you want 144 FPS or demanding games right away, buy the dedicated GPU now, even if that means using a somewhat weaker CPU. If Valorant is your only game for now, an APU such as a Ryzen 5 5600G—or a newer equivalent—should be enough.

Using integrated graphics first does not prevent you from installing a dedicated GPU later. The main downside is that integrated graphics are limited for modern games, and some high-end APUs can cost more than a similar CPU without integrated graphics. Compare the complete platform price, including RAM, motherboard, and future upgrade plans, rather than judging the CPU alone.

A used or inexpensive dedicated GPU can be a reasonable middle ground. Older dedicated cards are usually much faster than integrated graphics, but check their condition and power requirements carefully. Avoid overspending on a powerful CPU if you plan to pair it with a graphics card later; choose a balanced processor that will still suit your eventual GPU.