20 year old needs portfolio guidance

Dear all, I’m delighted to finally be a member of this wonderful forum. I’ve been a mute admirer.
About me: I’m a 20 year old person studying science. I’ve been investing a small amount belonging to my parents in stocks for 3 years now. I made a lot of mistakes, but as seniors have said, it’s my tuition fee to the market. I did get stock picks right but the portfolio allocation was insignificant. I now have a fairly concentrated portfolio. I’m still a novice and guidance would be immensely appreciated.
My portfolio:
Arihant capital markets-20%
Reason: Arihant capital markets is available at a price much cheaper than its peers like Emkay. It has a great offering, Good customer service, competitive brokerage rates. What also impressed me very much was it’s intuitive and aesthetically pleasing website . It’s the first point of contact for potential customers. In a bull run it’s expected that customers would transact more often, leading to increased brokerage earnings. Great presence all over India another encouraging factor. About 26000 equity clients seems quite impressive. Also, management remuneration is healthy and linked to performance of company which is a great incentive.I’m invested from 125 levels.
Sil investments: 15%
The sole factor that motivated me to invest in sil investments was the massive investment it holds in some decent companies. I do realise holding companies are not the best investment opportunities but it worked well for me.
Sumedha fiscal : 20 %
Sumedha fiscal is a nano cap available for 30 crore market cap. I was impressed by its excellent dividend yield. It derives majority of its income from investment banking. As the economy improves I believe companies would need a variety of services that are provided by investment banks. Big investment banks wouldn’t be interested in small ticket deals for small companies and that’s where Sumedha fiscal has a great market. It has zero debt and decent promoter holding. Also, nothing adverse has cropped up about management in my assessment.
Andhra petro: 12 %
I’veinvested because I believe this company is firmly on the path of turnaround. It’s India’s leading manufacturer of oxo alcohols. Demand is growing for these chemicals.Imposition of antidumping duty will help it immensely aiding improvement in sales and margin elevation. Decent management.
Vikas ecotech: 8%
I had invested after an order by NGT regarding lead consumption reduction. If I’m not mistaken it had ordered an exploratory study for reduction of lead which would benefit Vikas ecotech. But, nothing concrete has emerged yet. I’m at a no profit no loss level.
Cash:25 %