Present tense of what I did during the lockdown

Present tense is a tense expressing an action that is currently going on or habitually performed, or a state that currently or generally exists.

So you can use a sentence like this:
“I’m playing video games”

You can write in present tense by simply using the root form of the word. However, if you're writing in third person singular, you need to add -s, -ies, or -es. First person singular: I go swimming every day. Third person singular: She goes swimming every day.