What to do as an intermediate singer

I have been singing for about 2 years now, I took Chorus for 2 years in high school, but I have always been pretty good at singing. Taking Chorus has helped my confidence grow tremendously over the past year. But, even though people say I have a good voice, I personally don't like the sound of it. To me, it sounds groggy and not as smooth as I feel it should be. I'm definitely a mix between a Baritone and a Tenor. I can't sing super low notes, but I can sing higher notes like a tenor. Sometimes I have vibrato other times I really have to try, and just for that reason I feel I'm forcing it to happen which I believe is "fake vibrato". I can often hold straight-tone notes pretty well, except for some higher notes. The type of genre I mainly sing in is pop, but I occasionally sing songs that have an opera-type feel to it. What can I do to become a better singer within this genre and develop a less groggy voice and finally have a natural vibrato? I have never had voice lessons, so I don't know what I should be doing within the singing techniques, advanced exercises, and 30-day singer for my voice

Hi, Isaac! See below for a few articles with ideas for you:

Using the beginner course + developing a daily routine: https://www.30daysinger.com/blog/one-lesson-per-day-how-to-practice-for-the-best-results

Steps for self-study: https://www.30daysinger.com/blog/how-to-improve-your-singing-voice-steps-to-follow-for-self-study

Tracking improvement: https://www.30daysinger.com/blog/getting-better-fast-when-will-i-hear-improvement-in-my-voice

More tips: https://www.30daysinger.com/how-to-sing

I'd also recommend you check out any warmups or tutorials labelled "intermediate" or "advanced" for a challenge, and see the following tutorials specifically:

Classical style: https://www.30daysinger.com/tutorial/classical-singing/1

Vibrato, part 1: https://www.30daysinger.com/tutorial/mastering-vibrato/1

Vibrato, part 2: https://www.30daysinger.com/tutorial/how-to-sing-vibrato-part-2/1